Colorimetric Determination of Glucose based on BiVO4 Coupled with Gold Nanoparticles as a Photoactivated Mimic Enzyme of Oxidase

Background: The spectrophotometric detection of glucose usually requires the use of glucose oxidase (GOD) and horseradish peroxidase (HRP). These natural enzymes have specificity and can react with substrates efficiently and quickly, but their performance is easily influenced by external factors, such as humidity, temperature, and solution pH. In this study, no enzyme method was developed for the detection of glucose. Objective: In this work, gold nanoparticles (AuNPs) and BiVO4 were calcined onto the glass surface, offering excellent glucose oxidase-like activity under light irradiation. Coupled with silver nanoparticles (AgNPs), it can be applied to the colorimetric detection of glucose without the use of any natural enzyme. Methods: The heterostructure of AuNPs and BiVO4 onto glass substrate (G/AuNPs/BiVO4) was synthesized by deposition and calcination at 500°C. It exhibited oxidase-like activity towards glucose oxidation in the presence of oxygen (O2) under light irradiation and then generated gluconic acid and hydrogen peroxide (H2O2). The production of H2O2 could etch AgNPs, resulting in a clear color change of the solution. Results: A decrease in the absorbance showed a good linear relationship with glucose concentration in the range of 20-400 μM, with a detection limit of 5 μM. Conclusion: An enzyme-free method is proposed for the colorimetric detection of glucose. The photoactivated enzyme mimic of G/AuNPs/BiVO4 exhibited good recyclability with water rinsing. This is promising for wide applications in various fields.