A facile strategy to construct pure thiophene-sulfur-doped graphene/ZnO nanoplates sensitized structure for fabricating a novel “on-off-on” switch photoelectrochemical aptasensor

Improving inherent performance of photoactive materials and designing a novel detection strategy are crucial for achieving excellent photoelectrochemical (PEC) aptasensor. Herein, we present a facile thermal-treatment strategy for fabricating thiophene-sulfur-doped graphene/ZnO nanocomposite (t-SG/ZnO). In this nanoarchitecture, pure thiophene-sulfur-doped graphene (t-SG) acted as a novel enhanced carrier, which can effectively improve the visible light photoactivity and photostability of ZnO nanoplates by enhancing the interfacial charge transfer and decreasing the band gap of pure ZnO nanoplates. The as-prepared t-SG/ZnO nanocomposite exhibited higher photocurrent intensity, which was about 1.5 times and 2.6 times than that of nitrogen doped graphene/ZnO and graphene/ZnO, respectively. Furthermore, we have fabricated an “on-off-on” PEC aptasensing strategy for sensitive and selective determination of acetamiprid based on the outstanding PEC performance of t-SG/ZnO by using the aptamer technique as specific recognition. This PEC aptasensing strategy not only gives insights into using t-SG as a novel sensibilizer to improve the PEC nature of semiconductor but also offers a new PEC aptasensor platform for acetamiprid direct detection. This proposed method provides a promising flexible platform for pesticide detection.