Amperometric pH sensor based on Graphene-Polyaniline composite

Sha, R and Komori, K and Badhulika, Sushmee (2017) Amperometric pH sensor based on Graphene-Polyaniline composite. IEEE Sensors Journal. p. 1. ISSN 1530-437X (In Press)

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Abstract

Here we report a Graphene-Polyaniline (Gr-PANi) composite modified Glassy Carbon Electrode (GCE) as an amperometric pH sensor. Gr-PANi composite was synthesized by electro-deposition of PANi on the surface of Gr modified GCE using cyclic voltammetry (CV) technique. XRD and Raman analysis confirmed high crystallinity of Gr–PANi composite. FESEM analysis revealed that Gr flakes are surrounded by PANi film because of the heterogeneous nucleation and growth of PANi during electro-polymerization. In acidic region, current of the composite based pH sensor increased with decreasing pH values of the solution, whereas in alkaline region, current increased with the increasing pH values of the solution. The as-fabricated pH sensor exhibits shorter response time with an excellent sensitivity of −50.14 μA pH−¹ cm−² in the range of pH 1-5 and 139.2 μA pH−¹ cm−² in the range of pH 7-11. The composite based sensor showed enhanced sensitivity in compared to pure Gr based pH sensor because unlike pristine Gr based pH sensor, it utilizes both charge-storage mechanisms in EDLCs and pseudo-capacitors, thereby resulting in excellent synergy between Gr and PANi. Reproducibility of pH sensor was also examined between three different electrodes in the solution of pH 5. Insignificant variation in the current response suggested excellent reproducibility of pH sensor. To the best of our knowledge, no other studies have been reported on Gr-PANi composite based pH sensor over wide pH range. This Gr–PANi based pH sensor offers a simple, low cost, promising, real time amperometric pH sensor in chemistry, clinical diagnostics, bio-sensing and environmental monitoring applications.

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IITH Creators:

IITH Creators	ORCiD
Badhulika, Sushmee	UNSPECIFIED

Item Type:

Article

Uncontrolled Keywords:

Amperometric sensors, Chemical sensors, Electro-deposition, Electrodes, Graphene, Nano composite, Optical sensors, pH sensor, Polyaniline, Sensitivity, X-ray scattering

Subjects:

Electrical Engineering

Divisions:

Department of Electrical Engineering

Depositing User:

Team Library

Date Deposited:

24 Jul 2017 06:59

Last Modified:

30 Aug 2017 09:11

URI:

http://raiithold.iith.ac.in/id/eprint/3422