A ZnIn 2 S 4 @ReS 2 /AgInS 2 -based photoelectrochemical aptasensor for the ultrasensitive detection of kanamycin.

An ultrasensitive photoelectrochemical (PEC) aptasensor was originally designed by using ZnIn 2 S 4 /ReS 2 as a photoactive material and AgInS 2 as a signal amplifier. The signal amplifier AgInS 2 was incubated on the terminal of H-DNA (immobilized on the ZnIn 2 S 4 /ReS 2 /FTO surface), leading to an enhanced photocurrent response. Then, due to the introduction of DNA2, the formation of a double-stranded structure caused AgInS 2 to keep away from the electrode surface, and the photocurrent was reduced. In the presence of kanamycin, DNA2 was released from the system due to the competition relationship, and a restored photocurrent response was obtained. The combination of ZnIn 2 S 4 /ReS 2 and AgInS 2 accelerated the electron transfer and enhanced the separation efficiency of photogenerated electron-hole pairs, resulting in an improved performance of the PEC aptasensor, which was capable of accurate and sensitive detection of kanamycin in actual samples.