A biosensor for the sensitive and specific measurement of arsenite using gold nanoparticles

An electrochemical biosensor for arsenite concentration determination is developed in this study using arsenite oxidase (ArOx). Gold nanoparticles (AuNP) were used in this study to improve the analytical characteristics of the biosensor by providing a suitable nano-environment for the enzyme activity. The enzyme and the nanoparticles were electrodeposited on the glassy carbon (GC) working electrode to prepare the GC-AuNP-ArOx electrode. The linear measurement range of the biosensor was between 10(1) and 10(4) nM, while its detection limit was obtained equal to 5 nM. The effects of enzyme concentration, pH, storage temperature, and storage time on the biosensor's performance were investigated. Results showed that an enzyme concentration of 7 mu M at the physiological pH exerted the highest biosensor response (7 mu A anodic current/10 nM arsenite). No undesirable interference of heavy metals was observed on the biosensor response, and the biosensor showed excellent reproducibility compared to a conventional chemosensor.

Automated summary

An electrochemical biosensor using arsenite oxidase (ArOx) for arsenite concentration determination was developed in this study, with gold nanoparticles (AuNP) used to enhance the analytical characteristics. The biosensor showed a linear measurement range from 10(1) to 10(4) nM and a detection limit of 5 nM. It was found that an enzyme concentration of 7 µM at physiological pH resulted in the highest biosensor response, and the biosensor exhibited excellent reproducibility and minimal interference from heavy metals.