Dr Cheng Fang

Dr Cheng Fang

Senior Research Fellow

Global Centre for Environmental Remediation

Career Summary

Biography

Research Expertise
My research covers several multi-disciplines, from electrochemistry to prepare nano/micro-porous materials including semiconductors and noble metals, to sensors to monitor pollutants from waters water using SERS (surface-enhanced Raman scattering), AIE (aggregation induced emission), electrochemistry, nano-device (nanowire, nanogap, nanomembrane etc.), to environmental monitoring and remediation using advanced electrochemistry, nano-materials, lab-on-chip etc., to development of portable devices for field test and application. To strengthen my background, I have worked in several countries including China (-2004), Germany (2006-2006), Singapore (2006-2010) and Australia (2010-).

Qualifications

  • PhD, Wuhan University -China

Keywords

  • Advanced electrochemistry
  • Nano-materials for remediation and sensor
  • Nano-photonics (SERS + AIE)
  • Sensor for pollutant monitoring

Fields of Research

Code Description Percentage
030107 Sensor Technology (Chemical aspects) 35
030604 Electrochemistry 35
050206 Environmental Monitoring 30

Professional Experience

UON Appointment

Title Organisation / Department
Senior Research Fellow University of Newcastle
Global Centre for Environmental Remediation
Australia
Edit

Publications

For publications that are currently unpublished or in-press, details are shown in italics.


Journal article (57 outputs)

Year Citation Altmetrics Link
2017 Fang C, Megharaj M, Naidu R, 'Electrochemical Detection of Thioether-Based Fluorosurfactants in Aqueous Film-Forming Foam (AFFF)', Electroanalysis, 29 1095-1102 (2017) [C1]
DOI 10.1002/elan.201600724
Co-authors Ravi Naidu, Megh Mallavarapu
2017 Fang C, Megharaj M, Naidu R, 'Electrochemical Studies on Self-Assembled Monolayer (SAM) Upon Exposure to Anionic Surfactants: PFOA, PFOS, SDS and SDBS', Electroanalysis, 29 2155-2160 (2017) [C1]
DOI 10.1002/elan.201700108
Co-authors Ravi Naidu, Megh Mallavarapu
2017 Fang C, Megharaj M, Naidu R, 'Electrochemical switch on-off response of a self-assembled monolayer (SAM) upon exposure to perfluorooctanoic acid (PFOA)', JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 785 249-254 (2017) [C1]
DOI 10.1016/j.jelechem.2016.12.040
Citations Scopus - 1Web of Science - 1
Co-authors Megh Mallavarapu, Ravi Naidu
2017 Fang C, Megharaj M, Naidu R, 'Electrochemical Advanced Oxidation Processes (EAOP) to degrade per- and polyflluoroalkyl substances (PFASs)', JOURNAL OF ADVANCED OXIDATION TECHNOLOGIES, 20 (2017) [C1]
DOI 10.1515/jaots-2017-0014
Co-authors Megh Mallavarapu, Ravi Naidu
2017 Fang C, Dharmarajan R, Mallavarapu M, Naidu R, 'Gold nanoparticle-based optical sensors for selected anionic contaminants', Trends in Analytical Chemistry, 86 143-154 (2017) [C1]
DOI 10.1016/j.trac.2016.10.008
Citations Scopus - 3Web of Science - 1
Co-authors Raja Dharmarajan, Megh Mallavarapu, Ravi Naidu
2016 Fang C, Megharaj M, Naidu R, 'Surface-enhanced Raman scattering (SERS) detection of fluorosurfactants in firefighting foams', RSC Advances, 6 11140-11145 (2016) [C1]

© 2016 The Royal Society of Chemistry. We demonstrated SERS (surface-enhanced Raman scattering) detection of fluorosurfactants (FSs), which are commonly formulated in aqueous fir... [more]

© 2016 The Royal Society of Chemistry. We demonstrated SERS (surface-enhanced Raman scattering) detection of fluorosurfactants (FSs), which are commonly formulated in aqueous firefighting foams (AFFFs), by increasing their loading affinity and boosting their Raman activity. In order to increase FS's loading affinity, we introduced a cationic dye (ethyl violet or methyl blue) into the aqueous incubation solution to co-precipitate the FS onto the SERS substrate surface by forming an immiscible ion-pair (dye-FS). In the meantime, the Raman signal intensity was boosted due to the much higher Raman activity of the dye than that of FS. We compared two kinds of SERS substrate, patterned silver (Ag) surface and graphene oxide (GO) membrane, and noted the former (dye-FS-Ag) enhanced the Raman signal whilst the latter (dye-FS-GO) increased the loading affinity of the ion-pair due to the hydrophobic surface. We thus introduced silver nanoparticles (AgNPs) into the incubation solution (as well as dye) to co-precipitate FS onto the GO surface via an assembly of dye-FS-AgNP-GO. Using this assembly, we successfully detected FSs including pentadecafluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and 1H,1H,2H,2H-perfluorooctanesulfonic acid (6:2FTS), with a limit-of-detection (LOD) of ~50 ppb (~120 nM) for PFOA.

DOI 10.1039/c5ra26114g
Citations Scopus - 4Web of Science - 4
Co-authors Megh Mallavarapu, Ravi Naidu
2016 Fang C, Chen Z, Megharaj M, Naidu R, 'Potentiometric detection of AFFFs based on MIP', Environmental Technology & Innovation, 5 52-59 (2016) [C1]
DOI 10.1016/j.eti.2015.12.003
Co-authors Zuliang Chen, Megh Mallavarapu, Ravi Naidu
2016 Han M, Chen M, Ebendorff-Heidepriem H, Fang C, Qin A, Zhang H, et al., 'An optical fibre sensor for remotely detecting water traces in organic solvents', RSC Advances, 6 82186-82190 (2016) [C1]

© 2016 The Royal Society of Chemistry. Tetraphenylpyrazine-triphenylamine (TPP-TPA) was used to detect water traces in organic solvents by monitoring the shift of the fluorescenc... [more]

© 2016 The Royal Society of Chemistry. Tetraphenylpyrazine-triphenylamine (TPP-TPA) was used to detect water traces in organic solvents by monitoring the shift of the fluorescence peak wavelength. This wavelength based method avoids the intrinsic pro blems of fluorescence intensity change based methods. The use of optical fibres for the detection provides a remote and field-deployable sensing ability.

DOI 10.1039/c6ra17475b
Citations Scopus - 2Web of Science - 2
2016 Wang L, Fang C, Cheng Y, Lamb D, Chen Z, Megharaj M, Naidu R, 'A practical way to make solid-state reference electrodes', Journal of Bioanalytical Techniques, 1 1-5 (2016)
DOI 10.16966/jbt.101
Co-authors Megh Mallavarapu, Zuliang Chen, Liang Wang, Dane Lamb, Ravi Naidu
2016 Ruan S, Chen Y, Zhang P, Pan X, Fang C, Qin A, et al., 'Online remote monitoring of explosives by optical fibres', RSC Advances, 6 103324-103327 (2016) [C1]

© 2016 Royal Society of Chemistry. An AIE-active polytriazole coated fibre tip sensor was developed to detect picric acid with its detection limit down to 100 ppb. The fibre sens... [more]

© 2016 Royal Society of Chemistry. An AIE-active polytriazole coated fibre tip sensor was developed to detect picric acid with its detection limit down to 100 ppb. The fibre sensor requires an analysis time of only a few minutes and shows strong photostability and high reusability, and is promising for remote sensing of explosives in dangerous environments.

DOI 10.1039/c6ra24080a
2015 Yang C, Tang Y, Su Z, Zhang Z, Fang C, 'Preparation of Silver Nanowires via a Rapid, Scalable and Green Pathway', Journal of Materials Science and Technology, 31 16-22 (2015)

© 2014. Rapid synthesis of silver nanowires (Ag NWs) with high quality and a broad processing window is challenging because of the low selectivity of the formation of multiply tw... [more]

© 2014. Rapid synthesis of silver nanowires (Ag NWs) with high quality and a broad processing window is challenging because of the low selectivity of the formation of multiply twinned particles at the nucleation stage for subsequent Ag NWs growth. Herein we report a systematic study of the water-involved heterogeneous nucleation of Ag NWs with high rate (less than 20min) in a simple and scalable preparation method. Using glycerol as a reducing agent and a solvent with a high boiling point, the reaction is rapidly heated to 210°C in air to synthesize Ag NWs with a very high yield in gram level. It is noted that the addition of a small dose of water plays a key role for obtaining highly pure Ag NWs in high yield, and the optimal water/glycerol ratio is 0.25%. After investigating a series of forming factors including reaction temperature and dose of catalysts, the formation kinetics and mechanism of the Ag NWs are proposed. Compared to other preparation methods, our strategy is simple and reproducible. These Ag NWs show a strong Raman enhancement effect for organic molecules on their surface.

DOI 10.1016/j.jmst.2014.02.001
Citations Scopus - 9
2015 Wang L, Fang C, Wang K, 'Physiological Responses of Leymus Chinensis to Long-Term Salt, Alkali and Mixed Salt-Alkali Stresses', Journal of Plant Nutrition, 38 526-540 (2015)

© 2015, Copyright © Taylor & Francis Group, LLC. The aim of this study was to evaluate the physiological responses of Leymus chinensis (Trin.) Tzvel exposed to long-term s... [more]

© 2015, Copyright © Taylor & Francis Group, LLC. The aim of this study was to evaluate the physiological responses of Leymus chinensis (Trin.) Tzvel exposed to long-term salt, salt-alkali, and alkali stress in order to elucidate how L. chinensis can survive under alkaline-sodic soils. L. chinensis (30¿days after germination) were stressed with salt [SS; sodium chloride (NaCl)], mixed salt-alkali [MS; molar ratio of NaCl: sodium carbonate (Na 2 CO 3 ) = 2:1] and alkali salt (AS; Na 2 CO 3 ) at four different levels of sodium (Na + ) concentration (0, 75, 150, and 300¿mM) for 60¿days. L. chinensis showed 100% survival rate at all treatments except 300¿mM SS (33.3%) and AS (18.9%). The growth and physiological parameters of survival plants were measured. As anticipated, growth of L. chinensis was inhibited after stresses, which reflected in the decline of plant height, dry weight and tiller number following the increased Na + concentration. The content of Na + , proline, and soluble sugar in L. chinensis increased with the increasing Na + concentration, suggesting that L. chinensis need to accumulate inorganic and organic solutes for resisting osmotic stress induced by various salt stresses. These processes ensure the water balance that can provide a relative normal physiological environment for L. chinensis. Potassium (K + ) content of L. chinensis kept at a relative lower level than control to ensure the normal physiological processes. Chlorophyll content of stressed plant increased slightly compared to control plants, which can produce more energy for L. chinensis resisting various stresses. The increased malondialdehyde (MDA) content of stressed plants showed the damage of various stresses. Among the three treatments (SS, MS, and AS), the injury extent for L. chinensis can be expressed by AS > SS > MS, and MS was the most complicated for the counterbalance effects of soil electrical conduction and pH.

DOI 10.1080/01904167.2014.937874
Citations Scopus - 4
2015 Fang C, Megharaj M, Naidu R, 'Chemical oxidization of some AFFFs leads to the formation of 6:2FTS and 8:2FTS', Environmental Toxicology and Chemistry, 34 2625-2628 (2015) [C1]

© 2015 SETAC. The present study tested some aqueous film-forming foam (AFFF) products for the presence of or the potential to form 1H,1H,2H,2H-perfluorooctanesulfonic acid (6:2FT... [more]

© 2015 SETAC. The present study tested some aqueous film-forming foam (AFFF) products for the presence of or the potential to form 1H,1H,2H,2H-perfluorooctanesulfonic acid (6:2FTS) and 1H,1H,2H,2H-perfluorodecane sulfonic acid (8:2FTS). The results demonstrated the appearance of significant levels of 6:2FTS and 8:2FTS after the oxidization of those AFFFs. The authors concluded that fluorotelomer skeletons exist but are derived from those formulations of AFFFs.

DOI 10.1002/etc.3115
Citations Scopus - 8Web of Science - 8
Co-authors Ravi Naidu, Megh Mallavarapu
2015 Wang Z, Fang C, Mallavarapu M, 'Characterization of iron-polyphenol complex nanoparticles synthesized by Sage (Salvia officinalis) leaves', Environmental Technology and Innovation, 4 92-97 (2015)

© 2015 Elsevier B.V. In this paper iron-polyphenol complex nanoparticles (Fe-P NPs) were synthesized by Sage (Salvia officinalis) leaf extract, which have excellent adsorptive-fl... [more]

© 2015 Elsevier B.V. In this paper iron-polyphenol complex nanoparticles (Fe-P NPs) were synthesized by Sage (Salvia officinalis) leaf extract, which have excellent adsorptive-flocculation capacity for water treatment. They were characterized using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared Spectroscopy (FTIR) and X-ray diffraction (XRD) so that their surface properties could be understood. It was found that synthesized Fe-P NPs were cross-linked in colloid with spherical particles ranged from 5 to 25 nm. Their surfaces were capped with O-H groups. Dried powder derived from Fe-P NPs colloid can remain stable after several hours and then be partially oxidized to iron oxide on exposure to air. Removal of cationic dye ethyl violet with Fe-P NPs was tested to confirm that the surface charge on Fe-P NPs is positive.

DOI 10.1016/j.eti.2015.05.004
Citations Scopus - 3
Co-authors Megh Mallavarapu
2015 Wang L, Yang D, Fang C, Chen Z, Lesniewski PJ, Mallavarapu M, Naidu R, 'Application of neural networks with novel independent component analysis methodologies to a Prussian blue modified glassy carbon electrode array', Talanta, 131 395-403 (2015) [C1]
DOI 10.1016/j.talanta.2014.08.010
Citations Scopus - 4Web of Science - 3
Co-authors Zuliang Chen, Megh Mallavarapu, Ravi Naidu, Liang Wang
2015 Fang C, Xie Y, Johnston MR, Ruan Y, Tang BZ, Peng Q, Tang Y, 'SERS and NMR Studies of Typical Aggregation-Induced Emission Molecules', JOURNAL OF PHYSICAL CHEMISTRY A, 119 8049-8054 (2015) [C1]
DOI 10.1021/acs.jpca.5b05478
Citations Scopus - 5Web of Science - 5
2014 Wang Z, Yu C, Fang C, Mallavarapu M, 'Dye removal using iron-polyphenol complex nanoparticles synthesized by plant leaves', Environmental Technology and Innovation, 1-2 29-34 (2014)

© 2014 Elsevier B.V. This paper examined the ability of iron-polyphenol complex nanoparticles (Fe-P NPs) synthesized by eucalyptus leaf extracts as a novel adsorptive flocculant ... [more]

© 2014 Elsevier B.V. This paper examined the ability of iron-polyphenol complex nanoparticles (Fe-P NPs) synthesized by eucalyptus leaf extracts as a novel adsorptive flocculant to remove acid black 194 from aqueous solution. The influential parameters such as ratios of reagents, doses of Fe-P NPs, pH, temperatures and initial dye concentration were tested. The kinetics, experimental equilibrium and thermodynamic data for acid black 194 and Fe-P NPs systems were collected. The adsorption of dye on Fe-P NPs appears to be a physical process. This study confirms that removal of dye utilizing Fe-P NPs is more efficient than using traditional inorganic flocculant FeCl < inf > 3 < /inf > . The Fe-P NPs could be employed as inexpensive and low-toxic adsorptive flocculant for removing dye from water.

DOI 10.1016/j.eti.2014.08.003
Citations Scopus - 1
Co-authors Megh Mallavarapu
2014 Fang C, Shapter JG, Voelcker NH, Ellis AV, 'Graphene masks as passivation layers in the electrochemical etching of silicon', Journal of Materials Science, 49 7819-7823 (2014)

Site-specific masking with graphene films has the potential to facilitate low-cost, high-throughput micro-patterns on silicon substrates over large areas. Here, a facile approach ... [more]

Site-specific masking with graphene films has the potential to facilitate low-cost, high-throughput micro-patterns on silicon substrates over large areas. Here, a facile approach to using graphene as a masking agent on silicon wafers for site-specific patterning is demonstrated. Graphene sheets were deposited via a sealing-tape-exfoliation method onto hydride-terminated (Si-H) silicon substrates. Raman confocal mapping showed inhibition of oxidation of the Si wafer underlying the graphene, indicating that the graphene restricts the diffusion of oxygen onto the Si surface. The graphene coated Si substrates were then electrochemically etched in an aqueous HF/ethanol (3:1 (v/v)) anodization solution. Scanning electron microscopy showed that the graphene layer successfully restricted the etching of the Si surface, however, near the edge sites of the graphene deep etching occurred. © 2014 Springer Science+Business Media New York.

DOI 10.1007/s10853-014-8492-9
2014 Wang Z, Fang C, Megharaj M, 'Characterization of Iron-Polyphenol Nanoparticles Synthesized by Three Plant Extracts and Their Fenton Oxidation of Azo Dye', ACS SUSTAINABLE CHEMISTRY & ENGINEERING, 2 1022-1025 (2014)
DOI 10.1021/sc500021n
Citations Scopus - 33Web of Science - 26
Co-authors Megh Mallavarapu
2014 Fang C, Shapter JG, Voelcker NH, Ellis AV, 'Electrochemically prepared nanoporous gold as a SERS substrate with high enhancement', RSC Advances, 4 19502-19506 (2014)

Single-molecule surface-enhanced Raman scattering (SM-SERS) utilizes localized surface plasmons in metallic nanostructures for enhanced signal detection. This work demonstrates th... [more]

Single-molecule surface-enhanced Raman scattering (SM-SERS) utilizes localized surface plasmons in metallic nanostructures for enhanced signal detection. This work demonstrates the use of SM-SERS on an electrochemically anodized biocompatible nanoporous gold (NpAu) substrate using a bi-analyte Raman technique. It was found that the positions (so-called hot-spots) with the closest etched valley widths (w), or the smallest w/valley wall width (D) (ligaments), of the Au nanopores dominated the Raman scattering. By using an etched substrate with a w < 10 nm and a w/D < 0.2 an estimated enhancement factor of ~10 7 for both Nile blue and Rhodamine 6G dyes was achieved. Importantly, the bi-analyte Raman technique enabled the clear confirmation of single (or few) molecule detection on the Np/Au substrates. © the Partner Organisations 2014.

DOI 10.1039/c4ra01909a
Citations Scopus - 4
2013 Fang C, Bandaru NM, Ellis AV, Voelcker NH, 'Beta-cyclodextrin decorated nanostructured SERS substrates facilitate selective detection of endocrine disruptor chemicals', Biosensors and Bioelectronics, 42 632-639 (2013) [C1]
DOI 10.1016/j.bios.2012.10.075
Citations Scopus - 19
2013 Brodoceanu D, Fang C, Voelcker NH, Bauer CT, Wonn A, Kroner E, et al., 'Fabrication of metal nanoparticle arrays by controlled decomposition of polymer particles', Nanotechnology, 24 (2013) [C1]
DOI 10.1088/0957-4484/24/8/085304
Citations Scopus - 8
2013 Fang C, Shapter JG, Voelcker NH, Ellis AV, 'Ag2SO4 decorated with fluorescent Agn nanoclusters', Applied Surface Science, 270 77-81 (2013)

Here we report on the production of an Ag 2 SO 4 /Ag 2 O mixed-grain powder during the anodization of Ag foil in a HF-H 2 SO 4 electrolyte. We propose that there are three compe... [more]

Here we report on the production of an Ag 2 SO 4 /Ag 2 O mixed-grain powder during the anodization of Ag foil in a HF-H 2 SO 4 electrolyte. We propose that there are three competing reactions during the anodization process: (i) the production of Ag 2 O at the Ag foil anode surface from the presence of water in the electrolyte, (ii) the dissolution of the Ag 2 O in the presence of HF releasing Ag + ions, (iii) the precipitation of Ag + and SO 4 2- ions, as Ag 2 SO 4 on the Ag foil anode surface. This co-precipitation/dissolution process ultimately results in a mixed-grain powder. We then show that the Ag 2 O embedded within the mixed-grain is photo-decomposed to produce highly fluorescent silver nanoclusters (Ag n ) which decorate the Ag 2 SO 4 crystals. The Ag 2 SO 4 salt offers a stable matrix for the photo-decomposed Ag n nanoclusters to emit their strong fluorescence. © 2013 Elsevier B.V.

DOI 10.1016/j.apsusc.2012.12.097
Citations Scopus - 3
2013 Fang C, Brodoceanu D, Kraus T, Voelcker NH, 'Templated silver nanocube arrays for single-molecule SERS detection', RSC Advances, 3 4288-4293 (2013)

We describe the self-assembly of silver nanocubes (AgNC) into dense bowl-shaped arrays using a template made from polystyrene nanospheres (PSNS). Interestingly, we found that most... [more]

We describe the self-assembly of silver nanocubes (AgNC) into dense bowl-shaped arrays using a template made from polystyrene nanospheres (PSNS). Interestingly, we found that most AgNCs were arranged facet-to-facet. When used as substrates for surface-enhanced Raman scattering (SERS), we observed that the SERS hot spot positions were located at the corners of the cubes. This was confirmed using the formation of a self-assembled monolayer (SAM) of 1-dodecanethiol (DDT) covering the cubes' facet surface, whilst the pinholes in the DDT SAM at the corners were subsequently filled with 2-mercaptopyridine (MPy). Due to the high enhancement from the densely arranged AgNCs, single molecule detection was achieved from this SERS substrate and evidenced using the bi-analyte Raman technique. © The Royal Society of Chemistry 2013.

DOI 10.1039/c3ra22457k
Citations Scopus - 15
2012 Fang C, Ellis AV, Voelcker NH, 'Electrochemical synthesis of silver oxide nanowires, microplatelets and application as SERS substrate precursors', Electrochimica Acta, 59 346-353 (2012) [C1]
DOI 10.1016/j.electacta.2011.10.068
Citations Scopus - 19
2012 Fang C, Bandaru NM, Ellis AV, Voelcker NH, 'Electrochemical fabrication of nanoporous gold', Journal of Materials Chemistry, 22 2952-2957 (2012) [C1]
DOI 10.1039/c2jm14889g
Citations Scopus - 16
2011 Fang C, Ji H, Karen WY, Rafei SRM, 'Electrochemical detection of oligonucleotide by attaching redox probes onto its backbone', Biosensors and Bioelectronics, 26 2670-2674 (2011) [C1]

An approach was demonstrated to detect oligonucleotide by attaching redox probes onto its backbone. First, peptide nucleic acid (PNA) with a neutral backbone was immobilized onto ... [more]

An approach was demonstrated to detect oligonucleotide by attaching redox probes onto its backbone. First, peptide nucleic acid (PNA) with a neutral backbone was immobilized onto a gold (Au) electrode surface as a capture. Second, when the PNA capture hybridized with a target oligonucleotide (a short DNA), an assembly of Au-PNA-DNA formed and phosphate groups were thus brought into the assembly from the DNA's backbone. The linker ion of Zr 4+ exhibits a strong coordination interaction with the phosphate group and the carboxylic group. The hybridized target DNA provides the phosphate group while a derivatized redox probe of ferrocene (Fc) carboxyl acid offers the carboxylic group. Therefore, the redox probe can be attached to the phosphate group by the linker to form an assembly of Au-PNA-DNA-Zr-Fc. Its redox process was studied and the detection conditions of oligonucleotide were optimized. A limit of detection of 1.0×10 -12 M or ~2attomol was reached. © 2010 Elsevier B.V.

DOI 10.1016/j.bios.2010.03.017
Citations Scopus - 7
2011 Fang C, Ellis AV, Voelcker NH, 'Electrochemically prepared porous silver and its application in surface-enhanced Raman scattering', Journal of Electroanalytical Chemistry, 659 151-160 (2011)

We have demonstrated for the first time that silver can be electrochemically etched to form porous structures ranging from the nano- to the microscale. Silver wires, foils and fil... [more]

We have demonstrated for the first time that silver can be electrochemically etched to form porous structures ranging from the nano- to the microscale. Silver wires, foils and films deposited on a silicon wafer were etched in both acidic (HF) and basic (NH 3 ) N,N-dimethylformamide (DMF) solutions. We describe a possible etching mechanism for pore formation in which the convection within the etching solution focuses the etching current, while the organic solvent component stabilizes the nascent pore walls. Finally, the fabricated porous silver was shown to act as an effective substrate for surface-enhanced Raman scattering (SERS). © 2011 Elsevier B.V. All rights reserved.

DOI 10.1016/j.jelechem.2011.05.016
Citations Scopus - 21
2010 Neuzil P, Cheng F, Soon JBW, Qian LL, Reboud J, 'Non-contact fluorescent bleaching-independent method for temperature measurement in microfluidic systems based on DNA melting curves', Lab on a Chip, 10 2818-2821 (2010)

This report introduces a bleaching-independent temperature measurement method based on the analysis of the fluorescence emitted during the melting of DNA molecules with the SYBR-G... [more]

This report introduces a bleaching-independent temperature measurement method based on the analysis of the fluorescence emitted during the melting of DNA molecules with the SYBR-Green I intercalator, in a microvolume where the strong non-linearity of the signal is used to eliminate the photobleaching effect as well as to determine the heat transfer rate between a heater and the sample and the temperature non-uniformity within the sample. © 2010 The Royal Society of Chemistry.

DOI 10.1039/c005243d
Citations Scopus - 2
2009 Fang C, Agarwal A, Widjaja E, Garland MV, Wong SM, Linn L, et al., 'Metallization of silicon nanowires and SERS response from a single metallized nanowire', Chemistry of Materials, 21 3542-3548 (2009)

A simple method was demonstrated to metallize silicon (Si) nanowire (NW) just by dipping it into an aqueous deposition solution for several minutes. During the metallization proce... [more]

A simple method was demonstrated to metallize silicon (Si) nanowire (NW) just by dipping it into an aqueous deposition solution for several minutes. During the metallization process, metal ions were reduced and deposited on the top of the Si NW (where surface Si was oxidized). The surface silicon oxide was simultaneously dissolved and remov ed by hydrogen fluoride (HF), so that the deposition reaction was sustainable and controllable. The deposited silver (Ag) nanoparticles (NPs) uniformly self-assembled along the Si NW and developed into a metal covering with the NW as its core. Not only Ag + but also Cu 2+ , Pd 2+ , Co 2+ , Au 3- , and Pt 4- were deposited to metallize the Si NW using the simplified metallization process. Applications of the new nanocomposite materials were also explored. When the resulting Ag NP/Si NW was tested as a surface-enhanced raman scattering (SERS) substrate, an extremely strong signal was observed and a detection limit of ~600 molecules or 200-300 Ag NPs per laser spot was reached. The significantly enhanced SERS effect appears to be associated with the close packing of the neighboring NPs that self-assemble along the highly curved NW. © 2009 American Chemical Society.

DOI 10.1021/cm900132j
Citations Scopus - 46
2009 Fang C, Agarwal A, Ji H, Karen WY, Yobas L, 'Preparation of a SERS substrate and its sample-loading method for point-of-use application', Nanotechnology, 20 (2009)

A simple approach was demonstrated to prepare a silver (Ag) nanoparticle (NP) assembly as a SERS substrate. Just by dipping a flat silicon (Si) wafer into an aqueous deposition so... [more]

A simple approach was demonstrated to prepare a silver (Ag) nanoparticle (NP) assembly as a SERS substrate. Just by dipping a flat silicon (Si) wafer into an aqueous deposition solution of hydrogen fluoride (HF) +silver nitrate (AgNO 3 ), a monolayer of Ag NPs was uniformly deposited onto the Si wafer surface. In order to load the to-be-detected sample onto the as-prepared SERS substrate, three methods have been individually tested, (i)by incubating the SERS substrate in the sample solution, (ii)by dropping and drying a small volume of the sample solution (1-2µl) onto the SERS substrate surface, or (iii)by directly introducing the sample into the deposition solution. The last approach was also employed to metalize a Si nanowire (NW). Due to the NW's highly curved surface, the Ag NPs self-assembled and aggregated along the NW with a close interdistance. The aggregated Ag NPs on the NW surface can also be used as a SERS substrate. The demonstrated approach holds the promise to prepare a fresh SERS substrate at the point-of-use with the sample already loaded to promptly collect the SERS signal for the field application. © 2009 IOP Publishing Ltd.

DOI 10.1088/0957-4484/20/40/405604
Citations Scopus - 19
2008 Fang C, Fan Y, Kong J, Gao Z, Balasubramanian N, 'Electrical detection of oligonucleotide using an aggregate of gold nanoparticles as a conductive tag', Analytical Chemistry, 80 9387-9394 (2008)

Sequence-specific DNA detection is a routine job in medical diagnostics and genetic screening. Alternative to a fluorescence readout scheme or electrophoresis approach, various ki... [more]

Sequence-specific DNA detection is a routine job in medical diagnostics and genetic screening. Alternative to a fluorescence readout scheme or electrophoresis approach, various kinds of rapid, low-cost, facile, and label-free methods have also been developed in last decades. Among these, direct electrical detection of DNA received increasing attention but more research is desirable. Particularly, enhancement with high discrimination must be employed to selectively amplify the responding signal. A chip-based biosensor was developed in this work to electrically detect 22-mer oligonucleotide DNA at low concentration, from 50 fM to 10 pM. First, a gold nanoparticle (NP) was capped with 3-mercaptopropionic acid through a thiol-gold bond. The derivatized carboxylic acid group showed strong complex interaction with an inorganic linker, Zr 4+ . As a result, Zr 4+ could link several hundreds of individual gold NPs together to form an aggregate of nanoparticles (ANP), which was capable of being used as a conductive tag for the electrical detection of DNA. Second, in order to achieve the discriminative localization of ANP to bridge two comb-shaped electrodes (with height of ~50 nm and interdistance of 300-350 nm) gapped with insulative material of silicon oxide, peptide nucleic acids were covalently bonded to the silicon oxide in the gap as capture sites for DNA. After hybridization with target DNA, the charged phosphate-containing backbone of DNA was introduced into the gap. Phosphate groups also exhibited strong complex interaction with the linker of Zr 4+ and could react with the residual Zr 4+ on the ANP surface. As a consequence, the conductive tags were linked to the phosphate groups and localized into the gap, which could modify the conductance between the two comb-shaped electrodes in turn. The degree of modification correlated directly to the amount of hybridized DNA and to the concentration of target DNA in sample solution. Compared with the individual NPs used as the tag, a strong enhancement from the gold ANP was obtained. © 2008 American Chemical Society.

DOI 10.1021/ac801433z
Citations Scopus - 43
2008 Fang C, Fan Y, Kong JM, Gao ZQ, Balasubramanian N, 'Preparation of nanochain and nanosphere by self-assembly of gold nanoparticles', Applied Physics Letters, 92 (2008)

A self-assembly method is demonstrated to link nanoparticles into nanostructure of nanochain or nanosphere. Gold nanoparticles were covered with capping molecules by forming Au-S ... [more]

A self-assembly method is demonstrated to link nanoparticles into nanostructure of nanochain or nanosphere. Gold nanoparticles were covered with capping molecules by forming Au-S bonds with thiol group at one terminate. Another terminating group, carboxylic acid, showed strong complex interaction with inorganic linker Zr4+ to form covalent complex bond. The different nanostructures were obtained by moving a balance between two opposite interactions, the linking interaction of Zr4+ and the electrostatic repulsive interaction of net surface charge. When the capping molecule with different chain length was used, the linked nanochain feature exhibited a tunable interdistance between the neighboring nanoparticles. © 2008 American Institute of Physics.

DOI 10.1063/1.2955504
Citations Scopus - 18
2008 Fang C, Agarwal A, Buddharaju KD, Khalid NM, Salim SM, Widjaja E, et al., 'DNA detection using nanostructured SERS substrates with Rhodamine B as Raman label', Biosensors and Bioelectronics, 24 216-221 (2008)

A technique is demonstrated to detect DNA hybridization at low concentrations, based on Surface-Enhanced Raman Scattering (SERS) using silicon nanostructures coated with gold-silv... [more]

A technique is demonstrated to detect DNA hybridization at low concentrations, based on Surface-Enhanced Raman Scattering (SERS) using silicon nanostructures coated with gold-silver as substrate. Standard silicon process technologies were employed to fabricate the SERS substrates featuring nanogaps with a characteristic distance of 15 ± 10 nm. Target DNA was hybridized with cysteine-modified Peptide Nucleic Acids (PNA), which was previously fixed into the nanogaps as the capture sites. After hybridization, the introduced phosphate groups from the backbone of the target DNA showed strong affinity to an inorganic linker, Zr 4+ , so that resulting in the assembly substrate-PNA-DNA-Zr. Since PNA does not possess phosphate groups, the linker is avoided when there is no hybridization from the complimentary DNA. Subsequently, the assembly of substrate-PNA-DNA-Zr was incubated with a Raman label, Rhodamine B (RB). The carboxylic acid group in RB reacted with the linker Zr 4+ allowing this Raman Label to be attached to the assembly substrate-PNA-DNA-Zr. The Raman peaks corresponding to RB were selected to detect the target DNA, with a detection limit of 1 × 10 -12 M. © 2008 Elsevier B.V. All rights reserved.

DOI 10.1016/j.bios.2008.03.032
Citations Scopus - 89
2007 Fang C, Foca E, Xu S, Carstensen J, Föll H, 'Deep silicon macropores filled with copper by electrodeposition', Journal of the Electrochemical Society, 154 (2007)

Deep macropores in n-type Si have been completely filled with copper (Cu). Homogeneous metal deposition inside the deep pores was achieved by means of electroplating using a solut... [more]

Deep macropores in n-type Si have been completely filled with copper (Cu). Homogeneous metal deposition inside the deep pores was achieved by means of electroplating using a solution containing only Cu2 S O4 mixed with H2 S O4 and no additives. Initial nucleation of the Cu deposition was confined to the bottom of the pores and, by optimizing the filling conditions, uniform filling from the bottom to the top could be achieved. Macropores as deep as 150 µm with diameters in the 2 µm range could be filled with Cu, without encountering the so-called "bottleneck" effect. © 2006 The Electrochemical Society.

DOI 10.1149/1.2393090
Citations Scopus - 52
2007 Fang C, Foca E, Sirbu L, Carstensen J, Föll H, Tiginyanu IM, 'Formation of metal wire arrays via electrodeposition in pores of Si, Ge and III-V semiconductors', Physica Status Solidi (A) Applications and Materials Science, 204 1388-1393 (2007)

Deep straight macropores in n-type Si have been completely filled with copper (Cu). Homogeneous metal deposition inside the deep pores was achieved by means of electroplating usin... [more]

Deep straight macropores in n-type Si have been completely filled with copper (Cu). Homogeneous metal deposition inside the deep pores was achieved by means of electroplating using a solution containing only CuSO 4 mixed with H 2 SO 4 and an optimized process that begins at the bottom of the pores. Pores as deep as 150 iµm could be filled without encountering the so-called "bottleneck" effect. Straight macropores with diameters below 100 nm and extreme aspect ratios in InP could be filled with Cu using a pulsed process. Interconnected pores extending in the available set of (111) directions in {100} GaAs and forming domains could not be filled with Cu; instead the volume occupied by the pore domain was completely filled with Cu; i.e. the porous structure was destroyed. A possible reason for this new effect will be given. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA.

DOI 10.1002/pssa.200674352
Citations Scopus - 19
2007 Gao Z, Agarwal A, Trigg AD, Singh N, Fang C, Tung CH, et al., 'Silicon nanowire arrays for label-free detection of DNA', Analytical Chemistry, 79 3291-3297 (2007)

Arrays of highly ordered n-type silicon nanowires (SiNW) are fabricated using complementary metal-oxide semi-conductor (CMOS) compatible technology, and their applications in bios... [more]

Arrays of highly ordered n-type silicon nanowires (SiNW) are fabricated using complementary metal-oxide semi-conductor (CMOS) compatible technology, and their applications in biosensors are investigated. Peptide nucleic acid (PNA) capture probe-functionalized SiNW arrays show a concentration-dependent resistance change upon hybridization to complementary target DNA that is linear over a large dynamic range with a detection limit of 10 fM. As with other SiNW biosensing devices, the sensing mechanism can be understood in terms of the change in charge density at the SiNW surface after hybridization, the so-called "field effect". The SiNW array biosensor discriminates satisfactorily against mismatched target DNA. It is also able to monitor directly the DNA hybridization event in situ and in real time. The SiNW array biosensor described here is ultrasensitive, non-radioactive, and more importantly, label-free, and is of particular importance to the development of gene expression profiling tools and point-of-care applications. © 2007 American Chemical Society.

DOI 10.1021/ac061808q
Citations Scopus - 314
2007 Fang C, Fan Y, Kong JM, Zhang GJ, Linn L, Rafeah S, 'DNA-templated preparation of palladium nanoparticles and their application', Sensors and Actuators, B: Chemical, 126 684-690 (2007)

A versatile method, based on the metallization of DNA strands, is developed to prepare palladium nanoparticles on indium tin oxide (ITO) coated glass surface. Resulted palladium n... [more]

A versatile method, based on the metallization of DNA strands, is developed to prepare palladium nanoparticles on indium tin oxide (ITO) coated glass surface. Resulted palladium nanoparticles are distributed along the DNA strands and their size is controllable in the range of 10-100 nm. This is contrast to the branched palladium aggregates formed on bare ITO surface. When used as an electrochemical sensor, the nanoparticles show strong catalytic activity for the reduction of hydrogen peroxide and the oxidation of ascorbic acid, respectively. Higher catalytic activity is observed with the nanoparticles formed on double-stranded DNA (dsDNA) templates than those on single-stranded DNA (ssDNA) templates. © 2007 Elsevier B.V. All rights reserved.

DOI 10.1016/j.snb.2007.04.031
Citations Scopus - 27
2007 Fang C, Föll H, Carstensen J, Langa S, 'Electrochemical pore etching in Ge - An overview', Physica Status Solidi (A) Applications and Materials Science, 204 1292-1296 (2007)

While electrochemical pore etching in semiconductors has become a thriving field for research (and applications) in the past 15 years or so, little work has been done in Ge. Besid... [more]

While electrochemical pore etching in semiconductors has become a thriving field for research (and applications) in the past 15 years or so, little work has been done in Ge. Besides Si, Ge is the only semiconductor with a diffusion length large enough to enable the use of backside illumination, which has proved to be the decisive "trick" for the formation of excellent macropores in Si, and experiments in this vein have been conducted. However, Ge proved to behave in rather unexpected ways - the large body of pore etching knowledge obtained with Si and the III-V's was not directly applicable to Ge. While no good pores could be produced in most previous endeavours including our own, we finally succeeded in producing deep pores in n-type but also in p-type Ge of various doping levels and crystal orientations. A host of new and not yet totally understood phenomena was discovered. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA.

DOI 10.1002/pssa.200674312
Citations Scopus - 12
2006 Fang C, Föll H, Carstensen J, 'Electrochemical pore etching in germanium', Journal of Electroanalytical Chemistry, 589 259-288 (2006)

Nucleation and growth of electrochemically etched pores in Germanium (Ge) was investigated for n- and p-type Ge single crystals with {1 0 0}, {1 1 0}, and {1 1 1} orientations and... [more]

Nucleation and growth of electrochemically etched pores in Germanium (Ge) was investigated for n- and p-type Ge single crystals with {1 0 0}, {1 1 0}, and {1 1 1} orientations and doping concentrations of (10 14 -10 18 ) cm -3 . Various types of electrolytes, illumination conditions (front side, back side or none), and pre-treatments for optimizing nucleation were used. Several kinds of macropores could be obtained, mostly for the first time. In particular, pores could be obtained in p-type Ge samples. Pore geometries, morphologies, and growth peculiarities were found to be quite different from other semiconductors. Nucleation is generally difficult, the preferred growth direction is <1 0 0> or <1 1 1>, stop planes are of {1 1 0} type, and there is always a strong electropolishing component compromising pore geometry and stability. Porous membranes have been produced showing electrocapillarity effects. © 2006 Elsevier B.V. All rights reserved.

DOI 10.1016/j.jelechem.2006.02.021
Citations Scopus - 56
2006 Cheng F, Carstensen J, Föll H, 'Electrochemical pore etching in Ge', Materials Science in Semiconductor Processing, 9 694-700 (2006)

While electrochemical pore etching in semiconductors has become a thriving field for research and applications in the past 15 years or so, little work has been done in Ge. Besides... [more]

While electrochemical pore etching in semiconductors has become a thriving field for research and applications in the past 15 years or so, little work has been done in Ge. Besides Si, Ge is the only semiconductor with a minority carrier diffusion length large enough to enable the use of backside illumination, which has proved to be the decisive "trick" for the formation of excellent macropores in Si. First experiments in Ge have been performed, but Ge proved to behave in rather unexpected ways-the large body of pore etching knowledge obtained with Si and the III-V semiconductors was not directly applicable to Ge. While no good pores could be produced in most previous endeavors including our own, we finally succeeded in producing deep pores in n-type but also in p-type Ge of various doping levels and crystal orientations. In particular, it is now possible to create "good" macropores in a uniform distribution. A host of new and not yet totally understood phenomena was discovered, including pores of various kinds and crystallography. The paper will shortly outline the results obtained and relate it to what is known from other semiconductors under comparable circumstances. © 2006 Elsevier Ltd. All rights reserved.

DOI 10.1016/j.mssp.2006.08.017
Citations Scopus - 5
2006 Fang C, Föll H, Carstensen J, 'Long germanium nanowires prepared by electrochemical etching', Nano Letters, 6 1578-1580 (2006)

Germanium (Ge) nanowires have been produced by electrochemical etching of single-crystalline n-type Ge {100} in a HCI-containing aqueous electrolyte. Macropores could be etched at... [more]

Germanium (Ge) nanowires have been produced by electrochemical etching of single-crystalline n-type Ge {100} in a HCI-containing aqueous electrolyte. Macropores could be etched at various etching currents after an optimized procedure for homogeneous pore nucleation was used. Because of the narrow band gap of Ge (0.66 eV), the leakage current through pore walls is much higher than that, for example, in Si, leading to a constant dissolution of the pore walls. At sufficiently high current densities, it is then possible to form nanowires with diameters determined by the width of the space charge region, ranging from roughly 50 to 500 nm, and a length of several hundred micrometers. The role of the space charge region for stabilizing pore formation and in the formation of nanowires will be discussed. © 2006 American Chemical Society.

DOI 10.1021/nl061060r
Citations Scopus - 35
2004 Fang C, Wu B, Zhou X, 'Nafion membrane electrophoresis with direct and simplified end-column pulse electrochemical detection of amino acids', Electrophoresis, 25 375-380 (2004)

A novel electrophoresis technique, in which the separation column was replaced by a strip of Nafion membrane (5.0 cm × 0.20 mm × 0.25 mm), was developed for the separation of an... [more]

A novel electrophoresis technique, in which the separation column was replaced by a strip of Nafion membrane (5.0 cm × 0.20 mm × 0.25 mm), was developed for the separation of an amino acid mixture (glycine, asparic acid and lysine), followed by quadruple-pulse electrochemical detection. Nafion membrane contains hydrophilic pores (10-20 Å and 50-60 Å in size) acting as very narrow electrophoresis channels. The fixed-charge sites (-SO 3 - ) on the hydrophilic pore surface provide a strong charged background. A platinum disk electrode (0.90 mm inner diameter) was employed as the detection electrode and the electrophoresis cathode was used as the quasi-reference and counter electrode for the end-column electrochemical detector, without decoupler. Under optimized conditions the mixture of amino acids could be separated at a voltage of only 90 V with a detection limit of 10 -7 M, indicating that Nafion membrane electrophoresis is a potentially attractive technique for the separation of small organic molecules or ions.

DOI 10.1002/elps.200305740
Citations Scopus - 9
2003 Fang C, Zhou X, 'Voltammetry and EQCM Investigation of Glutathione Monolayer and its Complexation with Cu

The glutathione (GSH) self-assembled monolayer and its compexlation with Cu 2+ were studied by using voltammetry and EQCM. It was found that the monolayer could rearrange during ... [more]

The glutathione (GSH) self-assembled monolayer and its compexlation with Cu 2+ were studied by using voltammetry and EQCM. It was found that the monolayer could rearrange during the redox process of Cu 2+ /Cu + . The protonating, or not, of the carboxyl terminates of the adsorpted GSH molecules influence the compexlation interaction significantly for they are the key binding sites. The GSH monolayer had the capacity to accumulate Cu 2+ and the monolayer modified gold electrode was employed to detect the low levels of Cu 2+ with a limit of 1.0 × 10 -10 mol L -1 .

DOI 10.1002/elan.200302737
Citations Scopus - 26
2002 Fang C, Zhou XY, 'Electrochemical studies of glutathione monolayer assembled on a polycrystalline gold electrode', Wuhan University Journal of Natural Sciences, 7 102-106 (2002)

The glutathione (GSH) monolayer and complex monolayer of GSH-metallic ion on polycrystalline gold electrode were studied by using K 3 Fe(CN) 6 as the redox probe. As for the GSH ... [more]

The glutathione (GSH) monolayer and complex monolayer of GSH-metallic ion on polycrystalline gold electrode were studied by using K 3 Fe(CN) 6 as the redox probe. As for the GSH monolayer, it was found that the metallic ions could open the ion-gate in the monolayer dramatically in the order La 3+ > Pb 2+ »Ba 2+ > Ca 2+ whereas Zn 2+ ion closed the ion-gate. The complexes of GSH-metallic ions were capable of self-assembling the different kind of monolayer. All the differences were related to the structural configuration of the anchored GSH molecule, which changed with the different metallic ions or pH.

2001 He F, Shen W, Zhao W, Fang C, Fang Y, 'On-line monitoring in photocatalytic degradation of 4-chlorophenol by using cyclic voltammetry and UV-vis spectrometry', Chinese Journal of Catalysis, 22 168-170 (2001)

On-line monitoring in photocatalytic degradation process of organic compound 4-chlorophenol (4-CP) was carried out by using cyclic voltammetry and UV-Vis spectrometry. The result ... [more]

On-line monitoring in photocatalytic degradation process of organic compound 4-chlorophenol (4-CP) was carried out by using cyclic voltammetry and UV-Vis spectrometry. The result showed that the degradation process undertook at least a two-route mechanism to the complete mineralization: through redox pairs of benzoquinone(BQ) and hydrobenzoquinone(HQ) and of hydroxybenzoquinone(HBQ) and hydroxy-hydrobenzoquinone(HHQ). UV-Vis spectra taken at different time showed the breakage of benzene ring and the complete mineralization. The electroanalysis was proved to be a proper technique for on-line monitoring as it could detect simultaneously both initial reactants and intermediates, and thus it is suitable for on-line monitoring and complementary for mechanism study.

2001 Fang C, Liu YL, Zhou XY, 'The electrochemical properties of thionine adsorbed monolayer on gold electrode', Wuhan University Journal of Natural Sciences, 6 846-850 (2001)

A gold electrode modified with adsorbed thionine monolayer was investigated with ac impedance and cyclic voltammetry method. It was found there were some different redox propertie... [more]

A gold electrode modified with adsorbed thionine monolayer was investigated with ac impedance and cyclic voltammetry method. It was found there were some different redox properties for the adsorbed thionine depended on the different potential scanning rate. At the slower potential scanning rate (10 mV · s -1 ), the dimer of thionine appeared and possessed the catalytic activity for the oxidation of ascorbic acid. The underpotential deposition (UPD) and the bulk deposition of Cu 2+ were also employed to investigate the monolayer of adsorbed thionine.

2001 Fang C, Zhou X, 'The electrochemical characteristics of C

C 60 was covalently attached onto a self-assembly monolayer (SAM) of glutathione (GSH) formed on a Au electrode. Characterization of the resulting monolayer was carried out on a ... [more]

C 60 was covalently attached onto a self-assembly monolayer (SAM) of glutathione (GSH) formed on a Au electrode. Characterization of the resulting monolayer was carried out on a FT-IR spectrometer and its electrochemical properties were investigated with cyclic voltammetry and impedance methods. It was found that the pinholes on the C 60 -GSH monolayer showed the response of the opening and closing with the change of pH. The modified electrode can be used to determine NADH in neutral solution.

DOI 10.1002/1521-4109(200107)13:11&amp;lt;949::AID-ELAN949&amp;gt;3.0.CO;2-U
Citations Scopus - 19
2000 Wang J, Zeng B, Fang C, Zhou X, 'Influence of surfactants on the electron-transfer reaction at self-assembled thiol monolayers modifying a gold electrode', Journal of Electroanalytical Chemistry, 484 88-92 (2000)

Monolayer films of thiols with different terminal groups (-CH 3 , -COOH and -NH 2 ) were prepared on gold electrodes using a self-assembling procedure. Cyclic voltammetry was used... [more]

Monolayer films of thiols with different terminal groups (-CH 3 , -COOH and -NH 2 ) were prepared on gold electrodes using a self-assembling procedure. Cyclic voltammetry was used to investigate the electron-transfer reaction of potassium ferricyanide at the thiol modified gold electrode in the presence of surfactants. It was found that surfactants show some effects on the electron-transfer reaction at the thiol modified electrode. Cationic surfactants can improve the reversibility of a redox reaction at the thiol modified gold electrodes, while anionic surfactants cause a little inhibition of electron transfer of the redox at both methyl and carboxyl terminal thiol modified gold electrodes. Surfactants can interact with thiol monolayers in different ways, changing the structure and properties of the monolayer film, and can further affect electron transfer at the modified gold electrode.

DOI 10.1016/S0022-0728(00)00045-0
Citations Scopus - 57
2000 Wang J, Zeng BZ, Fang C, Zhou XY, 'Ion-gate Response of Glutathione Self-assembled Monolayer Modified on a Gold Electrode on the Activation of Surfactants', Kao Teng Hsueh Hsiao Hua Heush Hsueh Pao/ Chemical Journal of Chinese Universities, 21 1554 (2000)

Glutathione (GSH) was prepared on a gold electrode by self-assembled procedure. Cyclic voltammetry was used to investigate the electrochemical behavior of GSH self-assembled monol... [more]

Glutathione (GSH) was prepared on a gold electrode by self-assembled procedure. Cyclic voltammetry was used to investigate the electrochemical behavior of GSH self-assembled monolayer modified on a gold electrode on the activation of surfactants in potassium ferricyanide and benzoquinone (BQ) solution. It was found that GSH monolayer showed an ion-gate behavior in the presence of cationic surfactants and the electron transfer was improved with the increase of the concentration of cationic surfactants, which results from the fact that the interaction between the monolayer and surfactant changes the conformation of GSH monolayer. Anionic surfactant showed some inhibition to electron transfer at GSH monolayer modified gold electrode.

2000 Wang J, Zeng B, Fang C, Zhou X, 'Electrochemical characteristic of 2-mercaptobenzothiazole self-assembled monolayer on gold', Analytical Sciences, 16 457-461 (2000)

A monolayer membrane of 2-mercaptobenzothiazole (MBT) was prepared on a gold electrode through a self-assembly procedure. The monolayer structure and the electrochemical propertie... [more]

A monolayer membrane of 2-mercaptobenzothiazole (MBT) was prepared on a gold electrode through a self-assembly procedure. The monolayer structure and the electrochemical properties were investigated by various electrochemical techniques, like cyclic voltammetry and an impedance measurement with external redox. Experiments show that MBT can form a closely packed monolayer that can be charged due to the active N atom. The amount of charge on the membrane surface varies with the solution pH, and the monolayer shows 'opening and closing' which depends on the solution pH. The electrostatic interaction of the monolayer with other ions is also related to the pH in solution. An impedance analysis shows that the heterogeneous electron-transfer rate of a fast redox like Fe(CN) 6 (3-/4-) decreases from 1.2 x 10 -2 to 4.7 x 10 -5 cm s -1 in neutral solution due to blockage of the self-assembled monolayer membrane.

Citations Scopus - 36
2000 Wang J, Zeng B, Fang C, Zhou X, 'Voltammetric study of a cupric hexacyanoferrate monolayer immobilized on mixed dodecanethiol-glutathione self-assembled monolayer modified gold electrode', Electroanalysis, 12 763-766 (2000)

Mixed dodecanethiol-glutathinone self-assembled monolayers (DDT-GSH) were prepared on a gold electrode and further derivatized to form a monolayer of cupric hexacyanoferrate (CuHC... [more]

Mixed dodecanethiol-glutathinone self-assembled monolayers (DDT-GSH) were prepared on a gold electrode and further derivatized to form a monolayer of cupric hexacyanoferrate (CuHCF). Electrochemical behavior of the modified electrode was investigated by cyclic voltammetry. This inorganic monolayer modified electrode is electroactive and its surface concentration is 4.2x10 -10 mol cm -2 . It is observed that this modified electrode shows selectivity to potassium ion and exhibits an ideal Nernstian response with a slope of 60 mV/decade to potassium ions the range from 10 -2 to 1.0 mol L -1 .

DOI 10.1002/1521-4109(200006)12:10&amp;lt;763::AID-ELAN763&amp;gt;3.0.CO;2-N
Citations Scopus - 16
1999 Fang C, Tang X, Zhou X, 'Preparation of poly(malachite green) modified electrode and the determination of dopamine and ascorbic acid', Analytical Sciences, 15 41-46 (1999)

A novel glassy carbon electrode modified with Malachite Green was investigated. The modified electrode can be used to determine dopamine (DA) and ascorbic acid (AA). The anodic pe... [more]

A novel glassy carbon electrode modified with Malachite Green was investigated. The modified electrode can be used to determine dopamine (DA) and ascorbic acid (AA). The anodic peaks for ascorbic acid and dopamine were Separated (¿E(pa) about 200 mV) at the poly(malachite green) modified electrode. Thus, DA can be determined in the presence of AA.

Citations Scopus - 22
1999 Wang J, Zeng B, Fang C, He F, Zhou X, 'Electrochemical study of a polypyrrole film/decanethiol self-assembled monolayer on a gold electrode', Electroanalysis, 11 1345-1349 (1999)

Cyclic voltammetry and chronoamperometry were used to study the deposition of polypyrrole on a decanethiol self-assembled monolayer modified gold electrode (PPY/SAM/Au). The volta... [more]

Cyclic voltammetry and chronoamperometry were used to study the deposition of polypyrrole on a decanethiol self-assembled monolayer modified gold electrode (PPY/SAM/Au). The voltammetric behavior of the PPY/SAM film was investigated in the presence of several different electrolytes. It is found that the SAM shows great influence on the nucleation and growth of the PPY film The reaction of the SAM and the anions causes the different voltammetric behavior of the polymerization of pyrrole on the modified electrode Chronoamperometry shows the nucleation and growth of the PPY is initially inhibited but followed by a rapid increase. The SAM also influences electrochemical behavior of PPY film. Experiments show that the SAM can greatly depress the diffusion of anions in the PPY film and minimize the background capacitance current.

Citations Scopus - 15
1999 Cheng F, Xianbao W, Wuming Z, Xingyao Z, 'Several modified piezoelectric quartz crystals for determination of omethoate', Talanta, 49 253-259 (1999)

Determination of omethoate by modified PQC (piezoelectric quartz crystal) sensor is described. Several modified films were studied and compared. Omethoate of 0.1-10 ppm can be det... [more]

Determination of omethoate by modified PQC (piezoelectric quartz crystal) sensor is described. Several modified films were studied and compared. Omethoate of 0.1-10 ppm can be determined directly and sensitively with PVC-dioctyl sebacate film modified PQC. The modified crystal has good reversibility and reproductivity. The lifetime is about 1 month.

DOI 10.1016/S0039-9140(98)00375-0
Citations Scopus - 2
1998 Ye BX, Fang C, Zhou XY, 'Spectroelectrochemical study of hemoglobin at bare silver electrodes', Kao Teng Hsueh Hsiao Hua Heush Hsueh Pao/ Chemical Journal of Chinese Universities, 19 (1998)

This paper reports our recent study for the spectroelectrochemistry of hemoglobin at bare silver electrodes using a self-made long optical path UV/Visible thin-layer spectroelectr... [more]

This paper reports our recent study for the spectroelectrochemistry of hemoglobin at bare silver electrodes using a self-made long optical path UV/Visible thin-layer spectroelectrochemical cell. By this cell, the electron transfer number(n = 1. 04), the adsorbance (G = 8. 95 × 10 -14 mol/mm 2 ) and the formal redox potential (E 0 ' = 0. 14 V) of hemoglobin at bare silver electrodes were studied.

1996 Fang C, Zhang W, Zhou X, Lin Q, 'Determination of BSA by a piezoelectric crystal immunosensor and the washing of the electrode', Wuhan Daxue Xuebao/Journal of Wuhan University, 42 679-680 (1996)

The determination of BSA (bovine serum albumin)with a silver-plate quartz crystal microbalance(QCM) was discussed. The frequency shift was proprotional to the concentrations of BS... [more]

The determination of BSA (bovine serum albumin)with a silver-plate quartz crystal microbalance(QCM) was discussed. The frequency shift was proprotional to the concentrations of BSA in the range of 0. 5-50 mg/L. The reusability of the electrode was studied in detail. The 0. 2 mol/L glycine-HCl(pH = 2. 0)was selected as the washing solution.

Show 54 more journal articles

Conference (8 outputs)

Year Citation Altmetrics Link
2014 Wang Z, Yu C, Fang C, Megharaj M, 'Removal of acid red 94 and methylene blue using iron-polyphenol nanomaterials synthesized by various plant leaves: a comparison study', 2014 INTERNATIONAL CONFERENCE ON NANOSCIENCE AND NANOTECHNOLOGY (ICONN) (2014)
Citations Scopus - 1
Co-authors Megh Mallavarapu
2014 Fang C, Wang Z, Mallavarapu M, Naidu R, 'Self-assembling of nanocubes and nanoparticles', 2014 INTERNATIONAL CONFERENCE ON NANOSCIENCE AND NANOTECHNOLOGY (ICONN) (2014)
Co-authors Megh Mallavarapu, Ravi Naidu
2010 Soon JBW, Neuzil P, Fang C, Reboud J, Wong CC, Kao LT, 'High throughput melting curve analysis in monolithic silicon-based microfluidic device', 14th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2010, MicroTAS 2010 (2010)

This paper reports the development of a silicon-based microfluidic device that enables ultra fast melting curve analysis (MCA) for genomic studies (DNA) and drug discovery (protei... [more]

This paper reports the development of a silicon-based microfluidic device that enables ultra fast melting curve analysis (MCA) for genomic studies (DNA) and drug discovery (proteins). The system relies on the flow of nanoliter-sized discrete phase samples through a buried silicon channel. The samples are subjected to a temperature gradient generated by two external heaters along the channel. The channel also simultaneously serves as a light guide to illuminate the droplets and guide the emitted fluorescence to the detector outside the channel. The system provides a simple melting analysis of fluorescent-labeled molecular complexes, with high multiplexing capability and throughput. The chip-based solution is attractive due to nanolitre sized samples handling, resulting in fast heat transfer thus achieving ultra fast MCA for genomic studies and drug discoveries.

2008 Fang C, Agarwal A, Linn L, Balasubramanian N, 'Metallization of silicon nanowires and SERS response from a single metal-lized nanowire', 12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference (2008)

A simple method was developed to metallize silicon nanowires using an elec-troless displacement deposition reaction. The resulting metal nanoparticles were self-assembled along a ... [more]

A simple method was developed to metallize silicon nanowires using an elec-troless displacement deposition reaction. The resulting metal nanoparticles were self-assembled along a nanowire core to get a metal covering. The silver nanoparti-cles array aggregated along the nanowire was used as a SERS substrate. The en-hancement for SERS response was high even from a single metallized nanowire. The significantly high enhancement came from the close interdistance among the neighbouring nanoparticles aggregated along nanowire by self-assembly. © 2008 CBMS.

2007 Agarwal A, Fang C, Buddharaju KD, Balasubramanian N, Kwong DL, Khalid NM, et al., 'Highly ordered nanostructures for ultra-sensitive sers', TRANSDUCERS and EUROSENSORS '07 - 4th International Conference on Solid-State Sensors, Actuators and Microsystems (2007)

CMOS compatible silicon technologies are used to fabricate schematically arranged arrays of nanostructures for Surface Enhanced Raman Spectroscopy (SERS), incorporating processes ... [more]

CMOS compatible silicon technologies are used to fabricate schematically arranged arrays of nanostructures for Surface Enhanced Raman Spectroscopy (SERS), incorporating processes like DUV photolithography, reactive ion etching and physical vapour deposition of silver and gold. The surface treatment of cuvette and tubes used to handle Rhodamine 6G (R6G) and the substrate pre-treatment procedures, being significant for concentration less than 10 -9 M, are elaborated. The Raman signal is also enhanced by the addition of sodium chloride to R6G and by optimizing the sample immersion time in the analytes. 10 -10 and 10 -12 M R6G with 1mM sodium chloride is detected on silver and gold terminated SERS substrates respectively. ©2007 IEEE.

DOI 10.1109/SENSOR.2007.4300535
2007 Gao Z, Agarwal A, Trigg AD, Singh N, Fang C, Tung CH, Buddharaju KD, 'Silicon nanowire arrays for ultrasensitive label-free detection of DNA', TRANSDUCERS and EUROSENSORS '07 - 4th International Conference on Solid-State Sensors, Actuators and Microsystems (2007)

Arrays of highly ordered silicon nanowires (SiNWs) are fabricated using complementary metal-oxide semiconductor (CMOS) compatible technology and their applications in biosensors a... [more]

Arrays of highly ordered silicon nanowires (SiNWs) are fabricated using complementary metal-oxide semiconductor (CMOS) compatible technology and their applications in biosensors are investigated. The SiNW arrays show a concentration-dependent resistance change upon hybridization to complementary target DNA. As in the case of other SiNW biosensing devices, the sensing mechanism can be understood in terms of the change in charge density at the SiNW surface after hybridization, the so called "field effect". The SiNW arrays discriminate satisfactorily against mismatched target DNA. ©2007 IEEE.

DOI 10.1109/SENSOR.2007.4300555
Citations Scopus - 5
2007 Fang C, Carstensen J, Föll H, 'Electrochemical pore etching in n- And p-type Ge', Solid State Phenomena (2007)

Little was known about porous Ge until recently; here some substantial progress in producing porous Ge will be reported, mostly for the first time, i) n-type Ge in aqueous solutio... [more]

Little was known about porous Ge until recently; here some substantial progress in producing porous Ge will be reported, mostly for the first time, i) n-type Ge in aqueous solution: Pore geometries, morphologies and growth peculiarities were found to be quite different from other semiconductors, such as Si and III-V. Nucleation is generally difficult, the preferred growth direction is <100> (and <111>), major stop planes are of the {110} type, but others are also found. In addition, there is always a strong electropolishing component compromising pore geometry and stability, ii) n- and p-type Ge in organic solution: In DMSO solution, the growth direction is <111>, and the stopping planes are still mainly {110}; somewhat unexpected, because this has never been observed in Si, and because no pores have been found in other p-type semiconductors so far, with the exception of Si. Nucleation seems to be difficult too, and new domain-forming phenomena are observed. Smooth or rough pore walls can be obtained, dependent on the experimental conditions.

Citations Scopus - 5
2007 Carstensen J, Föl H, Foca E, Fang C, 'A stochastic model for current and voltage oscillations of the Si electrode', Solid State Phenomena (2007)

In this work we present a theoretical model that explains the current and voltage oscillations at the Si electrode in HF media. A simulation computer program based on this model i... [more]

In this work we present a theoretical model that explains the current and voltage oscillations at the Si electrode in HF media. A simulation computer program based on this model is implemented and results are shown. Oscillations of the current and (for the first time) the voltage obtained numerically fit perfectly with experiments. The model allows to obtain more information about the system in the form of maps (accompanied by histograms) of e.g.: oxide thickness distribution, SiO 2 /HF and Si/SiO 2 interfaces morphology, or local voltage losses. Other characteristics of the oxide like capacitance or roughness can also be obtained.

Citations Scopus - 1
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Research Supervision

Number of supervisions

Completed1
Current1

Total current UON EFTSL

PhD0.25

Current Supervision

Commenced Level of Study Research Title Program Supervisor Type
2017 PhD The Polymer Types of the Nanoplastics Particles in Wastewater, Sludge and Soil PhD (Environment Remediation), Faculty of Science, The University of Newcastle Co-Supervisor

Past Supervision

Year Level of Study Research Title Program Supervisor Type
2015 PhD Iron–Polyphenol Complex Nanoparticles Synthesized by Plant Leaves and Their Application in Environmental Remediation Environmental Studies, University of South Australia Principal Supervisor
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Research Collaborations

The map is a representation of a researchers co-authorship with collaborators across the globe. The map displays the number of publications against a country, where there is at least one co-author based in that country. Data is sourced from the University of Newcastle research publication management system (NURO) and may not fully represent the authors complete body of work.

Country Count of Publications
Australia 26
China 22
Singapore 13
Germany 11
Hong Kong 3
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Dr Cheng Fang

Position

Senior Research Fellow
Global Centre for Environmental Remediation
Global Centre for Environmental Remediation
Faculty of Science

Contact Details

Email cheng.fang@newcastle.edu.au
Phone (02)4913 8740

Office

Room ATC
Building Advanced Technology Centre.
Location Callaghan
University Drive
Callaghan, NSW 2308
Australia
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