Enhancement of bismuth tungstate perovskite photoelectrical performance using elemental co-doping and construction of ternary heterojunction for sensitive detection of Trenbolone.

Abstract

Bismuth tungstate perovskite has been identified as a promising photoelectric material. Nevertheless, the wide band gap of bismuth tungstate leads to short-wavelength absorption of a single material with an attenuated photocurrent response, hindering its realization in biosensing applications. In this study, F, S co-doped Bi₂WO₆ was synthesized by heat treatment and combined with SnS₂ and CdS to form a ternary heterojunction composite. The resulting composite material, marked as F, S-Bi₂WO₆@SnS₂@CdS, has excellent photoelectric characteristics. F, S co-doping can increase the number of oxygen vacancies, effectively reducing the band gap, and the introduction of narrow band gap metal-sulfur compounds can form ternary heterojunctions with them, further red-shifting the optical absorption wavelength, while greatly improving the photocurrent response through good energy level matching. The excellent level matching between AgInS₂ and F,S-Bi₂WO₆@SnS₂@CdS results in photocurrent enhancement. The competition between AgInS₂-Ab-TB and AgInS₂-Ab for limited binding sites leads to changes in the photocurrent signal, which can sensibly detect TB. The prepared PEC biosensor has excellent photocurrent response in the range of 0.1 pg/mL - 100 ng/mL, and the detection limit is 28.9 fg/mL. This study broadens the application of bismuth tungstate chalcogenide in biosensing and provides new ideas for the modification of other optoelectronic materials.