Abraham, Shiju and Srivastava, Saurabh and Kumar, Vinod and Pandey, Shobhit and Rastogi, Pankaj Kumar and Nirala, Narsingh R. and Kashyap, Sunayana and Srivastava, Sunil K. and Singh, Vidya Nand and Ganesan, Vellaichamy and Saxena, Preeti S. and Srivastava, Anchal (2015) Enhanced electrochemical biosensing efficiency of silica particles supported on partially reduced graphene oxide for sensitive detection of cholesterol. Journal of Electroanalytical Chemistry, 757. pp. 65-72. ISSN 1572-6657

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Abstract

The present work introduces partially reduced graphene oxide (pRGO)-silica (SiO2) particles hybrid system (pRGOSHs) for sensitive and cost effective free cholesterol detection. Fabricated out of thin layers of pRGOSHs, these proposed ChOx/pRGOSHs/ITO based biosensors have a detection range of 2.6-15.5 mM with an appreciable detection limit of 1.3 mM and sensitivity of 11.1 mu A/mM/cm(2). Low Michaelis-Menten constant (Km) (4.9 x 10(-4) mM) and high diffusivity constant (D) (3.2 x 10(-1) cm(2)/s) values clearly indicate enhanced immobilization of enzyme over the substrate. Additionally, electrochemical impedance studies indicate that the synergistic combination of SiO2 and pRGO also results in much lower impedance values (40% and 18% decrease in comparison to SiO2 and pRGO respectively) for an overall enhanced sensing performance. These results are further corroborated by the density functional theory based theoretical simulations indicating enhanced electron density (theoretically) in case of the proposed hybrid system. Finally, the present work also highlights the importance of Si-OH bonds formation in the proposed pRGOSHs composite system for attaining such enhanced biosensing ability.

Item Type:	Article
Uncontrolled Keywords:	Silica particles Partially reduced graphene oxide, cholesterol sensing Cyclic voltammetry Km value
Subjects:	Chemistry > Analytical Chemistry Electrochemistry
Divisions:	UNSPECIFIED
Depositing User:	Dr. Rajpal Walke
Date Deposited:	22 Sep 2016 06:59
Last Modified:	22 Sep 2016 06:59
URI:	http://npl.csircentral.net/id/eprint/1803

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