Microstructural and electrochemical impedance characterization of bio-functionalized ultrafine ZnS nanocrystals-reduced graphene oxide hybrid for immunosensor applications
IR@NPL: CSIR-National Physical Laboratory, New Delhi
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| Title |
Microstructural and electrochemical impedance characterization of bio-functionalized ultrafine ZnS nanocrystals-reduced graphene oxide hybrid for immunosensor applications
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| Creator |
Mishra, Sujeet K.
Srivastava, Avanish K. Kumar, Devendra Biradar, Ashok M. Rajesh, - |
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| Subject |
Chemistry
Materials Science Applied Physics/Condensed Matter Nanoscience/ Nanotechnology |
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| Description |
We report a mercaptopropionic acid capped ZnS nanocrystals decorated reduced graphene oxide (RGO) hybrid film on a silane modified indium-tin-oxide glass plate, as a bioelectrode for the quantitative detection of human cardiac myoglobin (Ag-cMb). The ZnS nanocrystals were anchored over electrochemically reduced GO sheets through a cross linker, 1-pyrenemethylamine hydrochloride, by carbodiimide reaction and have been characterized by scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy. The transmission electron microscopic characterization of the ZnS-RGO hybrid shows the uniform distribution of ultra-fine nanoparticles of ZnS in nano-sheets of GO throughout the material. The protein antibody, Ab-cMb, was covalently linked to ZnS-RGO nanocomposite hybrid for the fabrication of the bioelectrode. A detailed electrochemical immunosensing study has been carried out on the bioelectrode towards the detection of target Ag-cMb. The optimal fitted equivalent circuit model that matches the impedance response has been studied to delineate the biocompatibility, sensitivity and selectivity of the bioelectrode. The bioelectrode exhibited a linear electrochemical impedance response to Ag-cMb in a range of 10 ng to 1 mu g mL(-1) in PBS (pH 7.4) with a sensitivity of 177.56 Omega cm(2) per decade. The combined synergistic effects of the high surface-to-volume ratio of ZnS(MPA) nanocrystals and conducting RGO has provided a dominant charge transfer characteristic (R-et) at the lower frequency region of < 10 Hz showing a good biocompatibility and enhanced impedance sensitivity towards target Ag-cMb. The impedance response sensitivity of the ZnS-RGO hybrid bioelectrode towards Ag-cMb has been found to be about 2.5 fold higher than that of a bare RGO modified bioelectrode.
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| Publisher |
Royal Society of Chemistry
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| Date |
2013
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://npl.csircentral.net/3123/1/Microstructural%20and%20electrochemical%20impedance.pdf
Mishra, Sujeet K. and Srivastava, Avanish K. and Kumar, Devendra and Biradar, Ashok M. and Rajesh, - (2013) Microstructural and electrochemical impedance characterization of bio-functionalized ultrafine ZnS nanocrystals-reduced graphene oxide hybrid for immunosensor applications. Nanoscale, 5 (21). pp. 10494-10503. ISSN 2040-3364 |
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| Relation |
http://npl.csircentral.net/3123/
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