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

Abstract

We report biological procedure of synthesising nano-gold (AuNPs) over reduced graphene oxide (rGO) using physiologically important enzyme β galactosidase. The [email protected] NC was characterised using biophysical techniques. [email protected] 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/[email protected]/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.