Regular articleLight-addressable potentiometric sensor with gold nanoparticles enhancing enzymatic silver deposition for 1,5-anhydroglucitol determination

- A 1,5-AG LAPS sensor based on AuNPs enhancing enzymatic Ag deposition was developed.
- The 1,5-AG biosensor was characterized by SEM and XPS.
- The 1,5-AG sensor showed good linear relationship between ΔV and 1,5-AG concentration.
- The 1,5-AG sensor showed higher specificity and acceptable stability.

In this study, a light-addressable potentiometric sensor (LAPS) based on gold nanoparticles (AuNPs) enhancing enzymatic silver (Ag) deposition was developed for 1,5-anhydroglucitol (1,5-AG) determination. The pyranose oxidase enzyme (PROD), immobilized on the surface of AuNPs modified LAPS chip, could catalyze the hydrolysis of 1,5-AG and produce a reductive product H2O2 that enhanced the deposition of Ag. When a bias voltage was provided to the LAPS, a photocurrent which depended on the concentration of 1, 5-AG can be generated. Because the concentration of Ag ions in the electrolyte solution decreased with the deposition of metallic Ag on the surface of AuNPs modified LAPS chip, the potential shift (ΔV) has originated from local surface potential changes and reflected the changes of 1,5-AG concentration. The linear relationship between ΔV and 1,5-AG concentration were very well over the range from 60 μg/mL to 225 μg/mL with a correlation coefficient of 0.9977. The limit of detection was 40 μg/mL at signal/noise [S/N] = 3. In addition, LAPS detection system also showed higher specificity, acceptable stability and excellent recovery for 1, 5-AG detection.

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