A highly sensitive electrochemical glucose sensor structuring with nickel hydroxide and enzyme glucose oxidase

•A multilayered glucose biosensor with enhanced sensitivity was fabricated.•Combination of Ni2+/Ni3+ redox couple and glucose oxidase has been exploited for the first time.•Exhibits a lower detection limit of 100 nM with a high sensitivity of 16,840 μA mM−1 cm−2.•The surface shows a low Michaelis–Menten constant value of 2.4 μM.•Detailed mechanism of sensing was proposed and justified.

A multilayered glucose biosensor with enhanced electron transport was fabricated via the sequential electrodeposition of chitosan gold nanocomposite (CGNC) and nickel hydroxide (Ni(OH)2) on a bare gold electrode and subsequent immobilization of glucose oxidase. A thin film of Ni(OH)2 deposited on CGNC modified gold electrode serves as an electrochemical redox probe as well as a matrix for the immobilization of glucose oxidase retaining its activity. Electron transport property of CGNC has been exploited to enhance the electron transport between the analyte and electrode. Electrochemical characteristics of the biosensor were studied by cyclic voltammetry and chronoamperometry. Under optimal conditions the biosensor exhibits a linear range from 1 μM to 100 μM with a limit of detection (lod) down to 100 nM. The sensor shows a low Michaelis-Menten constant value of 2.4 μM indicates the high affinity of enzyme to the analyte points to the retained activity of enzyme after immobilization. The present glucose sensor with the high selectivity, sensitivity and stability is promising for practical clinical applications.

Graphical abstractA combination of Ni2+/Ni3+ redox couple and glucose oxidase has successfully been exploited for the realization of a highly sensitive glucose sensor for the first time.Figure optionsDownload full-size imageDownload as PowerPoint slide