Oxygen vacancy enhanced photoelectrochemical performance of Bi2MoO6/B, N co-doped graphene for fabricating lincomycin aptasensor.

Oxygen defect-engineered is an important strategy to improve the photoelectric activity of materials. Herein, a facile one-pot solvothermal method was utilized to synthesize visible light-responsive photoactive Bi2MoO6 nanoparticles anchored boron and nitrogen co-doped graphene (BNG) nanosheets nanocomposites with oxygen vacancy. The incorporation of BNG nanosheets increased the oxygen vacancies amounts on Bi2MoO6 remarkably, and the presences of oxygen vacancies can be beneficial to broaden the absorption range. The absorption edge of Bi2MoO6/BNG was widened from 500 nm to 550 nm compared to Bi2MoO6, and the charge transfer was accelerated to improve the photoactive of Bi2MoO6/BNG. Under visible light illumination, the photoelectrochemical (PEC) response of the as-prepared Bi2MoO6/BNG was 11.6-fold, 6.7-fold, 3.1-fold and 2.4-fold higher than that of pristine Bi2MoO6, Bi2MoO6/graphene, Bi2MoO6/nitrogen doped graphene and Bi2MoO6/boron doped graphene. Using Bi2MoO6/BNG nanocomposites with the superior PEC performance as photoactive materials in combination with specifically recognized lincomycin (LIN) aptamer, a highly efficient PEC aptasensor was successfully constructed for sensitive analysis of LIN. Under optimal conditions, the proposed PEC aptasensor exhibited excellent analytical performance for LIN with a wide linear response of 1 × 10-11 to 1 × 10-6 mol L-1 along with a low detection limit of 3.7 × 10-12 mol L-1 (defined as S/N = 3). The as-prepared Bi2MoO6/BNG nanocomposites exhibit excellent visible light response and PEC performance, indicating its potential applications in PEC biosensor.