A Label-Free Photoelectrochemical Aptasensor Based on N-GQDs Sensitized Zn-SnS2 for Aflatoxin B1 Detection

A new label-free aptasensor with high visible-light photoelectrochemical (PEC) activity was fabricated for the detection of AFB1 based on N-doped graphene quantum dots (N-GQDs) sensitized Zn-doped SnS2 (Zn-SnS2) nanocomposites. N-GQDs sensitized Zn-SnS2 showed an eminent PEC performance. Ascorbic acid was utilized as an efficient electron donor for scavenging photogenerated holes and inhibiting light driven electron-hole pair recombination. Under the optimum experimental conditions, the specific binding between AFB1 aptamer and AFB1 resulted in the linear decrease of photocurrent with the increase of logarithm of AFB1 concentration in the range of 0.01-20 ng mL-1 with a detection limit of 3 pg mL-1. The constructed N-GQDs sensitized Zn-SnS2 PEC aptasensor exhibited high sensitivity, low cost, and good reproducibility, which is a promising platform for the detection of other important analytes.