A molecularly imprinting photoelectrochemical sensor based on Bi 2 O 2 S-sensitized perovskite Cs 2 AgBiBr 6 for sarcosine determination.

An original molecular imprinting photoelectrochemical (PEC) sensor for sarcosine detection based on stable lead-free inorganic halide double perovskite Cs 2 AgBiBr 6 is proposed. Cs 2 AgBiBr 6 as a lead-free halide perovskite material possesses several positive optoelectronic properties for PEC analysis, such as long-lived component to the charge-carrier lifetime, and strong absorption of visible light. At the same time, two-dimensional materials also offer excellent electronic and mechanical properties; thus, Bi 2 O 2 S was used and combined with Cs 2 AgBiBr 6 to provide a stable and large photocurrent, which also benefits from the  stability of perovskite Cs 2 AgBiBr 6 . Based on this novel PEC assay, the detection range for sarcosine was between 0.005 and 5000 ng/mL with a low detection limit of 0.002 ng/mL. This work also improved the adhibition of metal halide perovskite in analytical chemistry field, providing a novel way for other small molecule detection.