Title: Enzymatically synthesised nano-gold decorated reduced graphene oxide for development of an enhanced glucose oxidase-based amperometric biosensor

Authors: Faizan Ahmed; Anas Anees; Qayyum Husain

Addresses: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, UP, India ' Department of Electrical Engineering, Faculty of Engineering, Aligarh Muslim University, Aligarh 202002, UP, India ' Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, UP, India

Abstract: We report biological procedure of synthesising nano-gold (AuNPs) over reduced graphene oxide (rGO) using physiologically important enzyme β galactosidase. The Au@rGO NC was characterised using biophysical techniques. Au@rGO immobilised with glucose oxidase (GOx) was achieved by drop-coating glassy carbon electrode surface with Nafion (Nf) as preservative membrane. EIS, amperometric response and cyclic voltammetry were used to determine electrochemical properties of the biosensor. The Nf/GOx/Au@rGO/GCE biosensor had sensitivity of 18.25 μA mM⁻¹ cm⁻² and linear range of 0.05-18 mM (R² = 0.997) with detection limit of 36 μM (S/N = 3). The response time over a period of 60 days depicted the biosensor to be quite stable. The potential of the bioelectrode in assessment of human blood glucose concentrations was compared with commercially available glucose sensors. The sensitivity and stability infer the biosensor is capable of functioning specifically in analysis of glucose in physiological fluids.

Keywords: β galactosidase; gold nanoparticles; reduced graphene oxide; rGO; green synthesis; biosensor.

DOI: 10.1504/IJBNN.2020.116332

International Journal of Biomedical Nanoscience and Nanotechnology, 2020 Vol.4 No.3/4, pp.206 - 221

Received: 16 Dec 2020
Accepted: 16 Dec 2020
Published online: 20 Jul 2021 *

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