Graphene based E. coli sensor on flexible acetate sheet

Basu, Palash Kumar and Indukuri, Deepthi and Keshavan, Sandeep and Navratna, Vikas and Vanjari, Siva Rama Krishna and Raghavan, Srinivasan and Bhat, Navakanta (2014) Graphene based E. coli sensor on flexible acetate sheet. In: SENSORS AND ACTUATORS B-CHEMICAL, 190 . pp. 342-347.

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Abstract

A low cost, reagent free, Escherichia coli sensor is demonstrated with graphene, on transparent flexible acetate substrate. Graphene is grown on 100 mu m thick Cu foil, using CVD process and subsequently transferred on to a flexible acetate substrate. Gold electrodes are deposited on graphene to form a two terminal, interdigitated capacitor structure. Impedance spectroscopy (10 Hz to 100 kHz) is performed to characterize the change in impedance, as a function of E. coli concentration on graphene surface. The residual methyl groups on graphene, resulting from the transfer process, act as binding sites for E. coli. It has been observed that the resistance of graphene decreases with increasing E. coli concentration. This is due to the increased hole doping induced by negatively charged E. coli. A sensitivity of 60% is achieved for an E. coli concentration of 4.5 x 10(7) cfu/ml. An equivalent RC model is proposed to explain the sensing mechanism. (C) 2013 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	SENSORS AND ACTUATORS B-CHEMICAL
Publisher:	ELSEVIER SCIENCE SA
Additional Information:	copyright for this article belongs to ELSEVIER SCIENCE SA SWITZERLAND
Keywords:	Graphene; Flexible substrate; E. coli sensor; Methyl group; RC model
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit Division of Chemical Sciences > Materials Research Centre Division of Electrical Sciences > Electrical Communication Engineering Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering
Date Deposited:	17 Dec 2013 09:18
Last Modified:	17 Dec 2013 09:18
URI:	http://eprints.iisc.ac.in/id/eprint/47933

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