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Mediator-free total cholesterol estimation using a bi-enzyme functionalized nanostructured gold electrode

IR@NPL: CSIR-National Physical Laboratory, New Delhi

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Title Mediator-free total cholesterol estimation using a bi-enzyme functionalized nanostructured gold electrode
 
Creator Sharma, Rachna
Sinha, R. K.
Agrawal, Ved Varun
 
Subject Chemistry
 
Description We report the fabrication of a bi-enzyme functionalized nanostructured Au electrode for the mediator-free determination of total cholesterol. A one-step electrochemical route for the synthesis, functionalization and deposition of Au nanostructures via the electroreduction of gold chloride onto indium tin oxide (ITO) coated glass plates has been proposed. The covalent biofunctionalization of the optimized Au electrode was done with cholesterol esterase (ChEt) and cholesterol oxidase (ChOx) to investigate the kinetic parameters and the sensing characteristics. The ChEt-ChOx/Glu-NanoAu/ITO bioelectrode has a surface-controlled electrode reaction with an electron transfer coefficient and a charge transfer rate constant of 0.68 and 7.09 s(-1), respectively. Under the optimal conditions, the bioelectrode undergoes a direct electron transfer reaction and exhibits a high sensitivity of 0.53 mA mM(-1) cm(-2) and a low detection limit of 1.57 mu M for cholesterol ester without the use of any redox mediator. In addition, the kinetic analysis reveals that the bioelectrode exhibits a surface concentration of 8.82 x 10(-12) mol cm(-2). The sensor has also been validated with clinical samples. The proposed biosensor shows good sensitivity, stability and selectivity towards total cholesterol and may thus find implications in the fabrication of biosensing devices.
 
Publisher Royal Society of Chemistry
 
Date 2015
 
Type Article
PeerReviewed
 
Format application/pdf
 
Identifier http://npl.csircentral.net/1899/1/206.pdf
Sharma, Rachna and Sinha, R. K. and Agrawal, Ved Varun (2015) Mediator-free total cholesterol estimation using a bi-enzyme functionalized nanostructured gold electrode. RSC Advances, 5 (52). 41786 -41794. ISSN 2046-2069
 
Relation http://npl.csircentral.net/1899/