1
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Park J, Kim JW, Kim H, Yoon W. An electrochemical hydrogen peroxide sensor for applications in nuclear industry. NUCLEAR ENGINEERING AND TECHNOLOGY 2021. [DOI: 10.1016/j.net.2020.06.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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2
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Groni S, Fave C, Schöllhorn B, Chapus L, Aubertin P, Touzalin T, Lucas IT, Joiret S, Courty A, Maisonhaute E. Long range self-organisations of small metallic nanocrystals for SERS detection of electrochemical reactions. J Electroanal Chem (Lausanne) 2020. [DOI: 10.1016/j.jelechem.2020.114322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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3
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Ma X, Fang C, Yan J, Zhao Q, Tu Y. A label-free electrochemiluminescent immunosensor for glutamate decarboxylase antibody detection on AuNPs supporting interface. Talanta 2018; 186:206-214. [DOI: 10.1016/j.talanta.2018.04.052] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 04/13/2018] [Accepted: 04/16/2018] [Indexed: 10/17/2022]
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4
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De SK, Mondal S, Sen P, Pal U, Pathak B, Rawat KS, Bardhan M, Bhattacharya M, Satpati B, De A, Senapati D. Crystal-defect-induced facet-dependent electrocatalytic activity of 3D gold nanoflowers for the selective nanomolar detection of ascorbic acid. NANOSCALE 2018; 10:11091-11102. [PMID: 29872830 DOI: 10.1039/c8nr03087a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Understanding and exploring the decisive factors responsible for superlative catalytic efficiency is necessary to formulate active electrode materials for improved electrocatalysis and high-throughput sensing. This research demonstrates the ability of bud-shaped gold nanoflowers (AuNFs), intermediates in the bud-to-blossom gold nanoflower synthesis, to offer remarkable electrocatalytic efficiency in the oxidation of ascorbic acid (AA) at nanomolar concentrations. Multicomponent sensing in a single potential sweep is measured using differential pulse voltammetry while the kinetic parameters are estimated using electrochemical impedance spectroscopy. The outstanding catalytic activity of bud-structured AuNF [iAuNFp(Bud)/iGCp ≅ 100] compared with other bud-to-blossom intermediate nanostructures is explained by studying their structural transitions, charge distributions, crystalline patterns, and intrinsic irregularities/defects. Detailed microscopic analysis shows that density of crystal defects, such as edges, terraces, steps, ledges, kinks, and dislocation, plays a major role in producing the high catalytic efficiency. An associated ab initio simulation provides necessary support for the projected role of different crystal facets as selective catalytic sites. Density functional theory corroborates the appearance of inter- and intra-molecular hydrogen bonding within AA molecules to control the resultant fingerprint peak potentials at variable concentrations. Bud-structured AuNF facilitates AA detection at nanomolar levels in a multicomponent pathological sample.
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Affiliation(s)
- Sandip Kumar De
- Chemical Science Division, Saha Institute of Nuclear Physics, Kolkata, West Bengal, India
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5
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Dewald C, Lüdecke C, Firkowska-Boden I, Roth M, Bossert J, Jandt KD. Gold nanoparticle contact point density controls microbial adhesion on gold surfaces. Colloids Surf B Biointerfaces 2017; 163:201-208. [PMID: 29304434 DOI: 10.1016/j.colsurfb.2017.12.037] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 12/15/2017] [Accepted: 12/19/2017] [Indexed: 11/27/2022]
Abstract
Surface structures in the nanometer range emerge as the next evolutionary breakthrough in the design of biomaterials with antimicrobial properties. However, in order to advance the application of surface nanostructuring strategies in medical implants, the very nature of the microbial repealing mechanism has yet to be understood. Herein, we demonstrate that the random immobilization of gold nanoparticles (AuNPs) on a material's surface generates the possibility to explore microbial adhesion in dependence of contact point densities at the biointerface between the microbe, i.e., Escherichia coli and the material's surface. By optimizing the contact point density defined by individual AuNPs, yet keeping the surface chemistry unchanged as evidenced by X-ray photoelectron spectroscopy, we show that the initial microbial adhesion can be successfully reduced up to 50%, compared to control (unstructured) surfaces. Furthermore, we observed a decrease in the size of microbial cells adhered to nanostructured surfaces. The results show that the spatial distance between the contact points plays a crucial role in regulating microbial adhesion, thus advancing our understanding of the microbial adhesion mechanism on nanostructured surfaces. We suggest that the introduced strategy for nanostructuring materials surfaces opens a research direction for highly microbial-resistant biomaterials.
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Affiliation(s)
- Carolin Dewald
- Chair of Materials Science (CMS), Otto Schott Institute of Materials Research (OSIM), Faculty of Physics and Astronomy, Friedrich Schiller University Jena, Löbdergraben 32, 07743, Jena, Germany; Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Bio Pilot Plant, Adolf-Reichwein-Straße 23, 07745, Jena, Germany; Jena School for Microbial Communication (JSMC), Neugasse 23, 07743, Jena, Germany
| | - Claudia Lüdecke
- Chair of Materials Science (CMS), Otto Schott Institute of Materials Research (OSIM), Faculty of Physics and Astronomy, Friedrich Schiller University Jena, Löbdergraben 32, 07743, Jena, Germany; Jena School for Microbial Communication (JSMC), Neugasse 23, 07743, Jena, Germany
| | - Izabela Firkowska-Boden
- Chair of Materials Science (CMS), Otto Schott Institute of Materials Research (OSIM), Faculty of Physics and Astronomy, Friedrich Schiller University Jena, Löbdergraben 32, 07743, Jena, Germany
| | - Martin Roth
- Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Bio Pilot Plant, Adolf-Reichwein-Straße 23, 07745, Jena, Germany; Jena School for Microbial Communication (JSMC), Neugasse 23, 07743, Jena, Germany
| | - Jörg Bossert
- Chair of Materials Science (CMS), Otto Schott Institute of Materials Research (OSIM), Faculty of Physics and Astronomy, Friedrich Schiller University Jena, Löbdergraben 32, 07743, Jena, Germany
| | - Klaus D Jandt
- Chair of Materials Science (CMS), Otto Schott Institute of Materials Research (OSIM), Faculty of Physics and Astronomy, Friedrich Schiller University Jena, Löbdergraben 32, 07743, Jena, Germany; Jena School for Microbial Communication (JSMC), Neugasse 23, 07743, Jena, Germany.
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6
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Electroreflectance study of potential dependent phase changes of dodecyl sulfate adlayer on a Au(1 1 1) Electrode. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2014.10.109] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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7
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Saeed AA, Singh B, Abbas MN, Issa YM, Dempsey E. Electrocatalytic Nitrite Determination Using Iron Phthalocyanine Modified Gold Nanoparticles. ELECTROANAL 2015. [DOI: 10.1002/elan.201400563] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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8
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Wang T, Fu Y, Tian H, Xiao Z, Hu J. Characterization of SH+ ions implantation-modified indium tin oxide films and its application for attachment of gold nanoparticles. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2014.07.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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9
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Lu J, Li H, Cui D, Zhang Y, Liu S. Enhanced Enzymatic Reactivity for Electrochemically Driven Drug Metabolism by Confining Cytochrome P450 Enzyme in TiO2 Nanotube Arrays. Anal Chem 2014; 86:8003-9. [DOI: 10.1021/ac502234x] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Jusheng Lu
- School of Chemistry and Chemical
Engineering, Southeast University, Nanjing 211189, People’s Republic of China
| | - Henan Li
- School of Chemistry and Chemical
Engineering, Southeast University, Nanjing 211189, People’s Republic of China
| | - Dongmei Cui
- School of Chemistry and Chemical
Engineering, Southeast University, Nanjing 211189, People’s Republic of China
| | - Yuanjian Zhang
- School of Chemistry and Chemical
Engineering, Southeast University, Nanjing 211189, People’s Republic of China
| | - Songqin Liu
- School of Chemistry and Chemical
Engineering, Southeast University, Nanjing 211189, People’s Republic of China
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10
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Muthukumar P, Abraham John S. Synergistic effect of gold nanoparticles and amine functionalized cobalt porphyrin on electrochemical oxidation of hydrazine. NEW J CHEM 2014. [DOI: 10.1039/c4nj00017j] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Muthukumar P, Abraham John S. Gold nanoparticles decorated on cobalt porphyrin-modified glassy carbon electrode for the sensitive determination of nitrite ion. J Colloid Interface Sci 2014; 421:78-84. [DOI: 10.1016/j.jcis.2014.01.030] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 12/28/2013] [Accepted: 01/23/2014] [Indexed: 11/26/2022]
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12
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Han X, Mendes SB. Optical impedance spectroscopy with single-mode electro-active-integrated optical waveguides. Anal Chem 2014; 86:1468-77. [PMID: 24417718 PMCID: PMC3983008 DOI: 10.1021/ac4030736] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An optical impedance spectroscopy (OIS) technique based on a single-mode electro-active-integrated optical waveguide (EA-IOW) was developed to investigate electron-transfer processes of redox adsorbates. A highly sensitive single-mode EA-IOW device was used to optically follow the time-dependent faradaic current originated from a submonolayer of cytochrome c undergoing redox exchanges driven by a harmonic modulation of the electric potential at several dc bias potentials and at several frequencies. To properly retrieve the faradaic current density from the ac-modulated optical signal, we introduce here a mathematical formalism that (i) accounts for intrinsic changes that invariably occur in the optical baseline of the EA-IOW device during potential modulation and (ii) provides accurate results for the electro-chemical parameters. We are able to optically reconstruct the faradaic current density profile against the dc bias potential in the working electrode, identify the formal potential, and determine the energy-width of the electron-transfer process. In addition, by combining the optically reconstructed faradaic signal with simple electrical measurements of impedance across the whole electrochemical cell and the capacitance of the electric double-layer, we are able to determine the time-constant connected to the redox reaction of the adsorbed protein assembly. For cytochrome c directly immobilized onto the indium tin oxide (ITO) surface, we measured a reaction rate constant of 26.5 s(-1). Finally, we calculate the charge-transfer resistance and pseudocapacitance associated with the electron-transfer process and show that the frequency dependence of the redox reaction of the protein submonolayer follows as expected the electrical equivalent of an RC-series admittance diagram. Above all, we show here that OIS with single-mode EA-IOW's provide strong analytical signals that can be readily monitored even for small surface-densities of species involved in the redox process (e.g., fmol/cm(2), 0.1% of a full protein monolayer). This experimental approach, when combined with the analytical formalism described here, brings additional sensitivity, accuracy, and simplicity to electro-chemical analysis and is expected to become a useful tool in investigations of redox processes.
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Affiliation(s)
- Xue Han
- Department of Physics and Astronomy, University of Louisville , Louisville, Kentucky 40292, United States
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13
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Yang J, Xu Y, He P, Fang Y. Direct Electrochemistry and Electrocatalysis of Hemoglobin on Aligned Carbon Nanotubes Based Electrodes Modified with Au Nanoparticles and SiO 2Gel. ELECTROANAL 2013. [DOI: 10.1002/elan.201300196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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14
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Raj MA, Revin SB, John SA. Synthesis, characterization and modification of functionalized pyrimidine stabilized gold nanoparticles on ITO electrode for the determination of tannic acid. Bioelectrochemistry 2013; 89:1-10. [DOI: 10.1016/j.bioelechem.2012.08.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2012] [Revised: 08/03/2012] [Accepted: 08/03/2012] [Indexed: 11/29/2022]
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15
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In situ synthesized gold nanoparticles for direct electrochemistry of horseradish peroxidase. Colloids Surf B Biointerfaces 2012; 104:181-5. [PMID: 23314493 DOI: 10.1016/j.colsurfb.2012.12.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 12/05/2012] [Accepted: 12/09/2012] [Indexed: 11/22/2022]
Abstract
In order to construct a three-dimensional electrode, in situ electrochemical deposition of gold nanoparticles onto a gold electrode coated with a self-assembled monolayer of 3-mercaptopropionic acid (Au NP/MPA/Au) was conducted. Horseradish peroxidase (HRP) was then immobilized into this three-dimensional electrode, leading to the realization of direct electron transfer of HRP. Scanning electron microscopy and electrochemical impedance spectroscopy were applied to characterize the electrode before and after HRP immobilization. The apparent Michaelis-Menten constant for immobilized HRP on a Au NP/MPA/Au electrode is 0.78 mM, indicating high enzymatic activity of HRP. The HRP modified electrode was further utilized as a sensing platform for the electrocatalytic reduction and detection of hydrogen peroxide. For the detection of hydrogen peroxide on this electrode, the sensitivity is 311.72 μA mM(-1) cm(-2), the detection limit is 0.16 μM, and the dynamic range is from 0.48 μM to 1.2 mM. Therefore this electrode is a promising device for sensitive and reproducible detection of H(2)O(2).
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16
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Satheesh Babu TG, Varadarajan D, Murugan G, Ramachandran T, Nair BG. Gold nanoparticle–polypyrrole composite modified TiO2 nanotube array electrode for the amperometric sensing of ascorbic acid. J APPL ELECTROCHEM 2012. [DOI: 10.1007/s10800-012-0416-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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17
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Kesavan S, Revin SB, John SA. Fabrication, characterization and application of a grafting based gold nanoparticles electrode for the selective determination of an important neurotransmitter. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm33013j] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Fabrication of conducting polymer-gold nanoparticles film on electrodes using monolayer protected gold nanoparticles and its electrocatalytic application. Electrochim Acta 2011. [DOI: 10.1016/j.electacta.2011.06.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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19
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Highly stable and sensitive glucose biosensor based on covalently assembled high density Au nanostructures. Biosens Bioelectron 2011; 26:3845-51. [DOI: 10.1016/j.bios.2011.02.044] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Revised: 02/23/2011] [Accepted: 02/24/2011] [Indexed: 11/18/2022]
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20
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Zhao J, Kong X, Shi W, Shao M, Han J, Wei M, Evans DG, Duan X. Self-assembly of layered double hydroxide nanosheets/Au nanoparticles ultrathin films for enzyme-free electrocatalysis of glucose. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1jm12060c] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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21
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Cruz LJ, Rueda F, Cordobilla B, Simón L, Hosta L, Albericio F, Domingo JC. Targeting Nanosystems to Human DCs via Fc Receptor as an Effective Strategy to Deliver Antigen for Immunotherapy. Mol Pharm 2010; 8:104-16. [DOI: 10.1021/mp100178k] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Luis J. Cruz
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Barcelona Science Park, Josep Samitier 1, 08028 Barcelona, Spain, Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain, Institute for Research in Biomedicine, Barcelona Science Park, Josep Samitier 10, 08028 Barcelona, Spain, and Department of Chemistry, University of Barcelona, Marti i Franques 1-11, 08028 Barcelona, Spain
| | - Felix Rueda
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Barcelona Science Park, Josep Samitier 1, 08028 Barcelona, Spain, Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain, Institute for Research in Biomedicine, Barcelona Science Park, Josep Samitier 10, 08028 Barcelona, Spain, and Department of Chemistry, University of Barcelona, Marti i Franques 1-11, 08028 Barcelona, Spain
| | - Begoña Cordobilla
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Barcelona Science Park, Josep Samitier 1, 08028 Barcelona, Spain, Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain, Institute for Research in Biomedicine, Barcelona Science Park, Josep Samitier 10, 08028 Barcelona, Spain, and Department of Chemistry, University of Barcelona, Marti i Franques 1-11, 08028 Barcelona, Spain
| | - Lorena Simón
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Barcelona Science Park, Josep Samitier 1, 08028 Barcelona, Spain, Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain, Institute for Research in Biomedicine, Barcelona Science Park, Josep Samitier 10, 08028 Barcelona, Spain, and Department of Chemistry, University of Barcelona, Marti i Franques 1-11, 08028 Barcelona, Spain
| | - Leticia Hosta
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Barcelona Science Park, Josep Samitier 1, 08028 Barcelona, Spain, Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain, Institute for Research in Biomedicine, Barcelona Science Park, Josep Samitier 10, 08028 Barcelona, Spain, and Department of Chemistry, University of Barcelona, Marti i Franques 1-11, 08028 Barcelona, Spain
| | - Fernando Albericio
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Barcelona Science Park, Josep Samitier 1, 08028 Barcelona, Spain, Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain, Institute for Research in Biomedicine, Barcelona Science Park, Josep Samitier 10, 08028 Barcelona, Spain, and Department of Chemistry, University of Barcelona, Marti i Franques 1-11, 08028 Barcelona, Spain
| | - Joan Carles Domingo
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Barcelona Science Park, Josep Samitier 1, 08028 Barcelona, Spain, Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain, Institute for Research in Biomedicine, Barcelona Science Park, Josep Samitier 10, 08028 Barcelona, Spain, and Department of Chemistry, University of Barcelona, Marti i Franques 1-11, 08028 Barcelona, Spain
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22
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Satheesh Babu TG, Suneesh PV, Ramachandran T, Nair B. Gold Nanoparticles Modified Titania Nanotube Arrays for Amperometric Determination of Ascorbic Acid. ANAL LETT 2010. [DOI: 10.1080/00032711003725615] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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23
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Assembly of ferrocenylhexanethiol functionalized gold nanoparticles for ascorbic acid determination. Mikrochim Acta 2010. [DOI: 10.1007/s00604-010-0410-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Oyama T, Yamaguchi S, Rahman MR, Okajima T, Ohsaka T, Oyama N. EQCM study of the [Au(III)Cl4](-)-[Au(I)Cl2](-)-Au(0) redox system in 1-ethyl-3-methylimidazolium tetrafluoroborate room-temperature ionic liquid. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:9069-9075. [PMID: 20163082 DOI: 10.1021/la904483y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The electrochemical behavior of the [Au(III)Cl(4)](-)-[Au(I)Cl(2)](-)-Au(0) redox system in room temperature ionic liquid (RTIL) of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF(4)) has been investigated quantitatively using an in situ electrochemical quartz crystal microbalance (EQCM) technique based on a Pt film-coated quartz crystal electrode (Pt-QCE). A series of two-electron (2e) and one-electron (1e) reductions of the [Au(III)Cl(4)](-) to [Au(I)Cl(2)](-) and [Au(I)Cl(2)](-) to Au metal were recognized at the Pt surface. Besides, the disproportionation reaction of [Au(I)Cl(2)](-) (i.e., the 2e-reduction product of [Au(III)Cl(4)](-)) to [Au(III)Cl(4)](-) and Au metal was also observed. Electro-dissolution of the Au deposited on the Pt electrode through a 1e-oxidation reaction in the presence of chloride ions was also confirmed using the Pt-QCE based EQCM technique. A 2e-oxidation reaction of [Au(I)Cl(2)](-) (i.e., the dissolved product) to [Au(III)Cl(4)](-) along with the oxidation of Cl(-) ion on the Pt surface was also realized at high anodic potential. The results demonstrate that in situ EQCM technique is applicable and powerful in elucidating electrochemical surface phenomena accompanying a mass change in RTIL.
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Affiliation(s)
- Taku Oyama
- Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259-G1-5 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan
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25
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Kannan P, John SA. Highly sensitive electrochemical determination of nitric oxide using fused spherical gold nanoparticles modified ITO electrode. Electrochim Acta 2010. [DOI: 10.1016/j.electacta.2010.01.084] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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26
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Nair SS, John SA, Sagara T. Simultaneous determination of paracetamol and ascorbic acid using tetraoctylammonium bromide capped gold nanoparticles immobilized on 1,6-hexanedithiol modified Au electrode. Electrochim Acta 2009. [DOI: 10.1016/j.electacta.2009.06.077] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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27
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Abraham John S, Sagara T. Short-time preparation and electrochemical properties of a single layer of tetraoctylammonium bromide capped Au nanoparticles on dithiol self-assembled monolayer-modified Au electrode. J Electroanal Chem (Lausanne) 2009. [DOI: 10.1016/j.jelechem.2009.05.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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28
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Jiang C, Elliott JM, Cardin DJ, Tsang SC. An electrochemical study of 4-aminothiophenol/pt nanoparticle multilayers on gold electrodes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:534-541. [PMID: 19053627 DOI: 10.1021/la802567a] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Quartz crystal microbalance (QCM) measurements of the formation of a 4-aminothiophenol (4-ATP) self-assembled monolayer (SAM) at a gold electrode showed that a surface coverage of 118 ng cm(-2) was obtained after a 3 h exposure period, indicating that good surface coverage was achieved. Cyclic voltammetry of the ferricyanide redox couple across this SAM modified surface produced similar results to those of a bare electrode; however, the electroreduction of oxygen was found to be impaired. The 4-ATP SAM layer was not stable to repeated electrochemical oxidation and reduction; it is believed that the 4-ATP SAM layer was first converted to a 4'-mercapto-N-phenylquinone diimine (NPQD) layer followed by subsequent formation of a 4'-mercapto-N-phenylquinone monoimine (NPQM) layer. We also report a quartz crystal microbalance study of the attachment of platinum nanoparticles to such SAM modified electrodes. We show that five times the amount of platinum nanoparticles can be attached to a 4-ATP modified electrode surface (observed frequency change -187 Hz) compared with an NPQD modified electrode surface (observed frequency change -35 Hz). The presence of the platinum particles was confirmed electrochemically by their surface electrochemical properties, which were different from those of the underlying gold electrode. It is believed that this is the first time that such direct evidence of electrochemical communication between platinum nanoparticles and a SAM modified electrode surface has been obtained. It was also shown to be possible to build up multilayer SAM/nanoparticle modified surfaces while maintaining efficient electrochemical communication. Up to three SAM/nanoparticle sandwich layers were constructed.
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Affiliation(s)
- Cuijie Jiang
- Department of Chemistry, The University of Reading, Whiteknights Campus, Reading, RG6 6AD, United Kingdom
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29
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Hosta L, Pla-Roca M, Arbiol J, López-Iglesias C, Samitier J, Cruz LJ, Kogan MJ, Albericio F. Conjugation of Kahalalide F with Gold Nanoparticles to Enhance in Vitro Antitumoral Activity. Bioconjug Chem 2008; 20:138-46. [DOI: 10.1021/bc800362j] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Leticia Hosta
- Institute for Research in Biomedicine; CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine; Institute for Bioengineering of Catalonia; and Scientific and Technical Services, Barcelona Science Park, University of Barcelona, Baldiri Reixac 10, 08028-Barcelona, Spain, Scientific and Technical Services, University of Barcelona, Lluis Solé i Sabaris 3-5, 08028 Barcelona, Spain, Department of Pharmacological and Toxicological Chemistry, Faculty of Chemistry and Pharmacy, Casilla 233,
| | - Mateu Pla-Roca
- Institute for Research in Biomedicine; CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine; Institute for Bioengineering of Catalonia; and Scientific and Technical Services, Barcelona Science Park, University of Barcelona, Baldiri Reixac 10, 08028-Barcelona, Spain, Scientific and Technical Services, University of Barcelona, Lluis Solé i Sabaris 3-5, 08028 Barcelona, Spain, Department of Pharmacological and Toxicological Chemistry, Faculty of Chemistry and Pharmacy, Casilla 233,
| | - Jordi Arbiol
- Institute for Research in Biomedicine; CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine; Institute for Bioengineering of Catalonia; and Scientific and Technical Services, Barcelona Science Park, University of Barcelona, Baldiri Reixac 10, 08028-Barcelona, Spain, Scientific and Technical Services, University of Barcelona, Lluis Solé i Sabaris 3-5, 08028 Barcelona, Spain, Department of Pharmacological and Toxicological Chemistry, Faculty of Chemistry and Pharmacy, Casilla 233,
| | - Carmen López-Iglesias
- Institute for Research in Biomedicine; CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine; Institute for Bioengineering of Catalonia; and Scientific and Technical Services, Barcelona Science Park, University of Barcelona, Baldiri Reixac 10, 08028-Barcelona, Spain, Scientific and Technical Services, University of Barcelona, Lluis Solé i Sabaris 3-5, 08028 Barcelona, Spain, Department of Pharmacological and Toxicological Chemistry, Faculty of Chemistry and Pharmacy, Casilla 233,
| | - Josep Samitier
- Institute for Research in Biomedicine; CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine; Institute for Bioengineering of Catalonia; and Scientific and Technical Services, Barcelona Science Park, University of Barcelona, Baldiri Reixac 10, 08028-Barcelona, Spain, Scientific and Technical Services, University of Barcelona, Lluis Solé i Sabaris 3-5, 08028 Barcelona, Spain, Department of Pharmacological and Toxicological Chemistry, Faculty of Chemistry and Pharmacy, Casilla 233,
| | - Luis J. Cruz
- Institute for Research in Biomedicine; CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine; Institute for Bioengineering of Catalonia; and Scientific and Technical Services, Barcelona Science Park, University of Barcelona, Baldiri Reixac 10, 08028-Barcelona, Spain, Scientific and Technical Services, University of Barcelona, Lluis Solé i Sabaris 3-5, 08028 Barcelona, Spain, Department of Pharmacological and Toxicological Chemistry, Faculty of Chemistry and Pharmacy, Casilla 233,
| | - Marcelo J. Kogan
- Institute for Research in Biomedicine; CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine; Institute for Bioengineering of Catalonia; and Scientific and Technical Services, Barcelona Science Park, University of Barcelona, Baldiri Reixac 10, 08028-Barcelona, Spain, Scientific and Technical Services, University of Barcelona, Lluis Solé i Sabaris 3-5, 08028 Barcelona, Spain, Department of Pharmacological and Toxicological Chemistry, Faculty of Chemistry and Pharmacy, Casilla 233,
| | - Fernando Albericio
- Institute for Research in Biomedicine; CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine; Institute for Bioengineering of Catalonia; and Scientific and Technical Services, Barcelona Science Park, University of Barcelona, Baldiri Reixac 10, 08028-Barcelona, Spain, Scientific and Technical Services, University of Barcelona, Lluis Solé i Sabaris 3-5, 08028 Barcelona, Spain, Department of Pharmacological and Toxicological Chemistry, Faculty of Chemistry and Pharmacy, Casilla 233,
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30
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Determination of nanomolar uric and ascorbic acids using enlarged gold nanoparticles modified electrode. Anal Biochem 2008; 386:65-72. [PMID: 19111516 DOI: 10.1016/j.ab.2008.11.043] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2008] [Revised: 11/20/2008] [Accepted: 11/26/2008] [Indexed: 11/21/2022]
Abstract
Individual and simultaneous determination of 50nM uric acid (UA) and ascorbic acid (AA) using enlarged, citrate-stabilized gold nanoparticles (AuNPs) self-assembled to 2,5-dimercapto-1,3,4-thiadiazole (DMT) monolayer modified Au (Au/DMT) electrode by an amperometric method is described for the first time. Self-assembly of AuNPs on the electrode surface was confirmed by atomic force microscopy (AFM), attenuated total reflectance FT-IR and diffuse reflectance spectral measurements. The electron transfer reaction (ETR) of [Fe(CN)(6)](3-/4-) was blocked at Au/DMT electrode, whereas it was restored with a peak separation of 200mV after the attachment of AuNPs on the Au/DMT (Au/DMT/AuNPs) electrode, which was confirmed from the ETR of the [Fe(CN)(6)](3-/4-) redox couple. When the self-assembled AuNPs were enlarged by hydroxylamine seeding, the ETR of [Fe(CN)(6)](3-/4-) was improved significantly with a peak separation of 100mV. Tapping mode AFM showed that the average size of the enlarged-AuNPs (E-AuNPs) was 50-70nm. The E-AuNPs modified electrode catalyzes the oxidation of AA and UA, separates their voltammetric signals by 200mV, and has excellent sensitivity towards AA and UA with a detection limit of 50nM. The practical application of the modified electrode was demonstrated by measuring the concentration of UA in blood serum and urine.
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31
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Sagara T. UV‐Visible Reflectance Spectroscopy of Thin Organic Films at Electrode Surfaces. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/9783527616817.ch2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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32
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Kannan P, Abraham John S. Synthesis of mercaptothiadiazole-functionalized gold nanoparticles and their self-assembly on Au substrates. NANOTECHNOLOGY 2008; 19:085602. [PMID: 21730726 DOI: 10.1088/0957-4484/19/8/085602] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Gold nanoparticles (AuNPs) stabilized with mercaptothiadiazole ligands, 2,5-dimercapto-1,3,4-thiadiazole (DMT), 5-amino-2-mercapto-1,3,4-thiadiazole (AMT) and 5-methyl-2-mercapto-1,3,4-thiadiazole (MMT), were prepared by the reaction of the respective ligands with HAuCl(4) and NaBH(4) in an aqueous medium. TEM images show that the average size of AuNPs was 6.5 ± 0.5 nm, irrespective of the capping ligands. The colloidal solution of both DMT-capped AuNPs (DMT-AuNPs) and AMT-capped AuNPs (AMT-AuNPs) were highly stable for several months. However, several changes were noticed for MMT-capped AuNPs (MMT-AuNPs) after 2 h from its formation. The SPR band intensity at 518 nm decreases and the narrow SPR absorption band slowly changes into a flat absorption pattern with a broad peak from 518 to 1000 nm which was accompanied by a colour change of the solution from red to purple and then blue and thereafter unchanged. The TEM image of MMT-AuNPs after 96 h shows that most of the spherical shape of the AuNPs assembled to form a nanowire-like structure. The observed changes may be due to the absence of a strong stabilizing force on the surface of the MMT-AuNPs. The amino and thiolate groups on the surface of the AMT-AuNPs and DMT-AuNPs, respectively, were directly self-assembled on Au electrodes. They exhibit excellent electrocatalytic activity towards the oxidation of AA by enhancing its oxidation current twice in addition to more than 200 mV negative shift in the oxidation potential in contrast to bare Au electrode.
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Affiliation(s)
- Palanisamy Kannan
- Department of Chemistry, Gandhigram Rural University, Dindigul, Gandhigram 624 302, India
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33
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Toyota A, Sagara T. Particle size dependence of the charging of Au nanoparticles immobilized on a modified ITO electrode. Electrochim Acta 2008. [DOI: 10.1016/j.electacta.2007.10.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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34
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Sivanesan A, Kannan P, Abraham John S. Electrocatalytic oxidation of ascorbic acid using a single layer of gold nanoparticles immobilized on 1,6-hexanedithiol modified gold electrode. Electrochim Acta 2007. [DOI: 10.1016/j.electacta.2007.07.020] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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35
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Spectroelectrochemical phenomena on surface plasmon resonance of Au nanoparticles immobilized on transparent electrode. Electrochim Acta 2007. [DOI: 10.1016/j.electacta.2007.03.029] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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36
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OHSAKA T, EL-DEAB MS. Electrocatalysis by Nanoparticles: Fabrication and Electrochemical Applications of Tailor-Designed Nanoparticles-Based Electrocatalysts. ELECTROCHEMISTRY 2007. [DOI: 10.5796/electrochemistry.75.858] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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37
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Wang F, Yuan R, Chai Y. A new amperometric biosensor for hydrogen peroxide determination based on HRP-nanogold-PTH-nanogold-modified carbon paste electrodes. Eur Food Res Technol 2006. [DOI: 10.1007/s00217-006-0386-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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38
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Toyota A, Sagara T. Time dependent spectral change upon potential step perturbation for Au nanoparticles immobilized on an organic monolayer-modified ITO electrode. Colloids Surf A Physicochem Eng Asp 2006. [DOI: 10.1016/j.colsurfa.2006.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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39
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Su L, Gao F, Mao L. Electrochemical Properties of Carbon Nanotube (CNT) Film Electrodes Prepared by Controllable Adsorption of CNTs onto an Alkanethiol Monolayer Self-Assembled on Gold Electrodes. Anal Chem 2006; 78:2651-7. [PMID: 16615776 DOI: 10.1021/ac051997x] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This paper describes electrochemical properties, such as electrode reactivity, electrode dimensions, and interfacial capacitance, of multiwalled carbon nanotube (MWNT) film electrodes prepared by controllable adsorption of the MWNTs onto the self-assembled monolayer (SAM) of n-octadecyl mercaptan (C18H37SH) deposited onto Au electrodes. The adsorption of the MWNTs onto the SAM-modified Au electrode substantially restores heterogeneous electron transfer between bare Au electrode and redox species in solution phase that is almost totally blocked by the SAM of C18H37SH, and as a result, the prepared MWNT/SAM-modified electrode possesses good electrode reactivity without a remarkable barrier to heterogeneous electron transfer. In addition, the surface coverage of the MWNTs is readily controlled by adjusting the immersion time for the adsorption of the MWNTs onto the SAM of C18H37SH, which essentially endows the prepared MWNT/SAM-modified electrodes with tunable electrode dimensions ranging from a nanoelectrode array to a macro-sized conventional electrode. On the other hand, the MWNT/SAM-modified electrode is found to possess a largely reduced interfacial capacitance, as compared with the MWNT film electrodes prepared with existing methods by directly confining the MWNTs onto electrode surface. This demonstration offers a new approach to fabrication of stable MWNT film electrodes with excellent electrochemical properties that are believed to be very attractive for electrochemical studies and electroanalytical applications.
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Affiliation(s)
- Lei Su
- Center for Molecular Science, Institute of Chemistry, the Chinese Academy of Sciences, Beijing 100080, China
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40
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Doherty WJ, Wysocki RJ, Armstrong NR, Saavedra SS. Potential-Modulated, Attenuated Total Reflectance Spectroscopy of Poly(3,4-ethylenedioxythiophene) and Poly(3,4-ethylenedioxythiophene Methanol) Copolymer Films on Indium−Tin Oxide. J Phys Chem B 2006; 110:4900-7. [PMID: 16526729 DOI: 10.1021/jp056230n] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report the first application of a potential-modulated spectroelectrochemical ATR (PM-ATR) instrument utilizing multiple internal reflections at an optically transparent electrode to study the charge-transfer kinetics and electrochromic response of adsorbed films. A sinusoidally modulated potential waveform was applied to an indium-tin oxide (ITO) electrode while simultaneously monitoring the optical reflectivity of thin (2-6 equivalent monolayers) copolymer films of poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-ethylenedioxythiophene methanol) (PEDTM), previously characterized in our laboratory. At high modulation frequencies the measured response of the polymer film is selective toward the fastest electrochromic processes in the film, presumably those occurring within the first adsorbed monolayer. Quantitative determination of the electrochromic switching rate, derived from the frequency response of the attenuated reflectivity, shows a linear decrease in the rate, from 11 x 10(3) s(-1) to 3 x 10(3) s(-1), with increasing proportions of PEDTM in the copolymer, suggesting that interactions between the methanol substituent on EDTM and the ITO surface slow the switching process by limiting the rate of conformational change in the polymer film.
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Affiliation(s)
- Walter J Doherty
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721, USA
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41
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Abdelrahman AI, Mohammad AM, Okajima T, Ohsaka T. Fabrication and Electrochemical Application of Three-Dimensional Gold Nanoparticles: Self-Assembly. J Phys Chem B 2006; 110:2798-803. [PMID: 16471888 DOI: 10.1021/jp056238x] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Multilayers film of nanostructured citrate-stabilized gold particles (AuNPs) has been fabricated based on the layer-by-layer (LBL) technique using a self-assembled monolayer of 1,4-benzenedimethanethiol (BDMT). The formation of AuNPs and BDMT self-assemblies as alternative multilayers was confirmed by transmission electron microscopy (TEM), X-ray photoelectron spectroscope (XPS), and quartz crystal microbalance (QCM). The formation of uniform AuNP layers with an average monolayer thickness of 5-6 nm was obvious in the TEM images. The existence of BDMT molecules as cross linkers for the AuNPs' layers was proved by XPS measurements. The greater affinity of AuNPs' layers to bind BDMT molecules in comparison with the bare Au bulk electrode was revealed by QCM measurements. Electrochemically, the AuNPs' layers on the electrode surface did not only catalyze the reduction of oxygen (ca. 100-mV positive shift of the reduction peak potential compared with that at the bare Au bulk electrode) but also showed a fascinating nature of working as a renewed activated-electrode surface; a zigzag response was observed for oxygen reduction during alternative immobilization of BDMT and the AuNP layer. The self-assembly of a new AuNPs layer restored the catalytic activity that was entirely blocked by the preceding BDMT layer.
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Affiliation(s)
- Ahmed I Abdelrahman
- Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8502, Japan
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42
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Mineshige A. ELECTROCHEMISTRY 2006; 74:397-401. [DOI: 10.5796/electrochemistry.74.397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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43
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Sagara T, Nagatani H. ELECTROCHEMISTRY 2006; 74:512-517. [DOI: 10.5796/electrochemistry.74.512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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44
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Zhao J, Bradbury CR, Huclova S, Potapova I, Carrara M, Fermín DJ. Nanoparticle-Mediated Electron Transfer Across Ultrathin Self-Assembled Films. J Phys Chem B 2005; 109:22985-94. [PMID: 16853995 DOI: 10.1021/jp054127s] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The electrochemical behavior of arrays of Au nanoparticles assembled on Au electrodes modified by 11-mercaptoundecanoic acid (MUA) and poly-L-lysine (PLYS) was investigated as a function of the particle number density. The self-assembled MUA and PLYS layers formed compact ultrathin films with a low density of defects as examined by scanning tunneling microscopy. The electrostatic adsorption of Au particles of 19 +/- 3 nm on the PLYS layer resulted in randomly distributed arrays in which the particle number density is controlled by the adsorption time. In the absence of the nanoparticles, the dynamics of electron transfer involving the hexacynoferrate redox couple is strongly hindered by the self-assembled film. This effect is primarily associated with a decrease in the electron tunneling probability as the redox couple cannot permeate through the MUA monolayer at the electrode surface. Adsorption of the Au nanoparticles dramatically affects the electron-transfer dynamics even at low particle number density. Cyclic voltammetry and impedance spectroscopy were interpreted in terms of classical models developed for partially blocked surfaces. The analysis shows that the electron transfer across a single particle exhibits the same phenomenological rate constant of electron transfer as for a clean Au surface. The apparent unhindered electron exchange between the nanoparticles and the electrode surface is discussed in terms of established models for electron tunneling across metal-insulator-metal junctions.
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Affiliation(s)
- Jianjun Zhao
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
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45
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Raj C, Abdelrahman AI, Ohsaka T. Gold nanoparticle-assisted electroreduction of oxygen. Electrochem commun 2005. [DOI: 10.1016/j.elecom.2005.06.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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46
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Huo SJ, Li QX, Yan YG, Chen Y, Cai WB, Xu QJ, Osawa M. Tunable Surface-Enhanced Infrared Absorption on Au Nanofilms on Si Fabricated by Self-Assembly and Growth of Colloidal Particles. J Phys Chem B 2005; 109:15985-91. [PMID: 16853028 DOI: 10.1021/jp052585v] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Au colloids were used to fabricate nanoscale-tunable Au nanofilms on silicon for surface-enhanced IR absorption bases in both ambient and electrochemical environments. This wet process incorporates the self-assembly of colloidal Au monolayer using 3-aminopropyl trimethoxysilane as the organic coupler with subsequent chemical plating in an Au(III)/hydroxylamine solution. FTIR spectroscopy in transmission mode of the probe species SCN- was used to evaluate the apparent surface enhancement in IR absorption of 2D Au colloid arrays and chemically plated Au particles. The nanostructure of Au films was examined by atomic force microscopy. The IR and AFM results show that the apparent surface enhancement factor (1-2 orders of magnitude) increases with increasing sizes and/or contact, and the severe aggregation of Au nanoparticles may cause the bipolar band shape. Cyclic voltammetry on the Au nanofilm obtained by the above nucleation and growth strategy exhibits a feasible electrochemical stability and behavior. In situ ATR-FTIR measurement of p-nitrobenzoic acid adsorption demonstrates that the as-grown Au film yields rather promising surface enhancement as well.
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Affiliation(s)
- Sheng-Juan Huo
- Shanghai Key Laboratory for Molecular Catalysis and Innovative Materials and Department of Chemistry, Fudan University, Shanghai 200433, China
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47
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Luo XL, Xu JJ, Zhang Q, Yang GJ, Chen HY. Electrochemically deposited chitosan hydrogel for horseradish peroxidase immobilization through gold nanoparticles self-assembly. Biosens Bioelectron 2005; 21:190-6. [PMID: 15967368 DOI: 10.1016/j.bios.2004.07.029] [Citation(s) in RCA: 226] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2004] [Revised: 06/07/2004] [Accepted: 07/22/2004] [Indexed: 11/26/2022]
Abstract
A new strategy for immobilization of horseradish peroxidase (HRP) has been presented by self-assembling gold nanoparticles on chitosan hydrogel modified Au electrode. From a mildly acidic chitosan solution, a chitosan film is electrochemically deposited on Au electrode surface via a negative voltage bias. This process is accompanied by the hydrogen evolution reaction, and the released hydrogen gas made the deposited chitosan film with porous structure, which facilitates the assembly of gold nanoparticles and HRP. The resulting substrates were characterized by atomic force microscopy (AFM) and electrochemical impedance spectroscopy (EIS). The immobilized HRP displayed an excellent catalytic property to the reduction of H2O2 in the presence of methylene blue mediator. The resulting biosensor (HRP-modified electrode) showed a wide dynamic range of 8.0 microM-15 mM H2O2, and the linear ranges were 8.0 microM-0.12 mM and 0.50-12 mM, with a detection limit of 2.4 microM estimated at a signal-to-noise ratio of 3. Moreover, the biosensor remained about 85% of its original sensitivity after four weeks' storage.
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Affiliation(s)
- Xi-Liang Luo
- The Key Lab of Analytical Chemistry for Life Science, Institute of Analytical Science, Department of Chemistry, Nanjing University, 22 Hankou Road, Nanjing 210093, P.R. China
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48
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Bae AH, Numata M, Hasegawa T, Li C, Kaneko K, Sakurai K, Shinkai S. 1D Arrangement of Au Nanoparticles by the Helical Structure of Schizophyllan: A Unique Encounter of a Natural Product with Inorganic Compounds. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200462810] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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49
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Bae AH, Numata M, Hasegawa T, Li C, Kaneko K, Sakurai K, Shinkai S. 1D Arrangement of Au Nanoparticles by the Helical Structure of Schizophyllan: A Unique Encounter of a Natural Product with Inorganic Compounds. Angew Chem Int Ed Engl 2005; 44:2030-3. [PMID: 15736237 DOI: 10.1002/anie.200462810] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Ah-Hyun Bae
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 812-8581, Japan
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50
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Potential-Driven Dynamic Behavior of Surface Modified Gold Nanoparticles at a Au(111) Electrode Surface. E-JOURNAL OF SURFACE SCIENCE AND NANOTECHNOLOGY 2005. [DOI: 10.1380/ejssnt.2005.141] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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