A ZnIn2S4@ReS2/AgInS2-based photoelectrochemical aptasensor for the ultrasensitive detection of kanamycin

Abstract

An ultrasensitive photoelectrochemical (PEC) aptasensor was originally designed by using ZnIn₂S₄/ReS₂ as a photoactive material and AgInS₂ as a signal amplifier. The signal amplifier AgInS₂ was incubated on the terminal of H-DNA (immobilized on the ZnIn₂S₄/ReS₂/FTO surface), leading to an enhanced photocurrent response. Then, due to the introduction of DNA2, the formation of a double-stranded structure caused AgInS₂ 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 ZnIn₂S₄/ReS₂ and AgInS₂ 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.