Rathee Solanki, Pratima and Kaushik, Ajeet and Manaka, T. and Pandey, Manoj Kumar and Iwamoto, M. and Agrawal, Ved Varun and Malhotra, Bansi Dhar (2010) Self-assembled monolayer based impedimetric platform for food borne mycotoxin detection. Nanoscale , 2 (12). 2811-2817 . ISSN 2040-3372

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Abstract

A self-assembled monolayer (SAM) of 11-amino-1-undecanethiol (AUT) has been fabricated onto a gold (Au) substrate to co-immobilize anti-ochratoxin-A antibodies (AO-IgGs) and bovine serum albumin (BSA) to detect food borne mycotoxin [i.e., ochratoxin-A (OTA)]. AUT/Au electrode, AO-IgGs/AUT/Au immunoelectrode and BSA/IgGs/AUT/Au immunoelectrode have been characterized using scanning electron microscopy (SEM) and electrochemical studies such as cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). Electrochemical studies reveal that the AUT-SAM with NH2 groups provide favorable conditions to immobilize AO-IgGs with better orientation, resulting in enhanced electron transport to obtain improved sensing characteristics. The EIS response studies of the BSA/AO-IgGs/AUT/Au immunoelectrode obtained as a function of OTA concentration reveal that the value of the charge transfer resistance (RCT) increases with increased OTA concentration. The BSA/AO-IgGs/AUT/Au immunoelectrode exhibits linearity over 0.5–6.0 ng/dl, detection limit of 0.08 ng/dl using 3σb/m criteria, response time of 30 s and sensitivity of [similar]36.83 Ω/ng dl−1 cm−2 with a regression coefficient of 0.999. Attempts have been made to monitor the change in RCT of BSA/AO-IgGs/AUT/Au immunoelectrode on addition of coffee samples.

Item Type:	Article
Subjects:	Biochemistry & Molecular Biology Chemistry Materials Science Physics
Divisions:	UNSPECIFIED
Depositing User:	Ms Neetu Chandra
Date Deposited:	09 Jul 2012 06:54
Last Modified:	09 Jul 2012 06:54
URI:	http://npl.csircentral.net/id/eprint/303

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