Label-free “signal-off” PEC aptasensor for determination of kanamycin based on 3D nanoflower-like FeIn 2 S 4 /CdS Z-scheme heterostructures

Highly photoactive 3D nanoflower-like FeIn 2 S 4 /CdS heterostructures were synthesized by hydrothermal treatment and low-temperature cation exchange. The FeIn 2 S 4 /CdS displayed 14.5 times signal amplification in contrast to FeIn 2 S 4 alone. It was applied as a photoactive substrate to construct a label-free photoelectrochemical (PEC) aptasensor for ultrasensitive determination of kanamycin (KAN). Under the optimal conditions, the constructed PEC aptasensor displayed a wide linear range (5.0 × 10 −4 ~ 5.0 × 10 1 ng mL −1 ) and a low detection limit ( S / N = 3) of 40.01 fg mL −1 . This study provides some constructive insights for preparation of advanced photoactive materials and exhibits great potential for quantitative determination of antibiotics in foods and environmental samples. Graphical Abstract