Signal-off photoelectrochemical aptasensor for kanamycin: Strand displacement reaction combines p-n competition

Asignal-off photoelectrochemical aptasensor based on p-n type semiconductor competitive quenching effect and strand displacement reaction was constructed for the determination of kanamycin. Au NPs@MgIn2S4-graphene composite was used as n-type photoactive semiconductor material. In the presence of the kanamycin, strand displacement reaction was triggered and the p-type CuInS2 quantum dots labeled aptamer was introduced on the Au NPs@MgIn2S4-graphene surface. The CuInS2 quantum dots can competitive consume the electron donors (AA) and light energy of the PEC system, thus quenched the anodic photocurrent of Au NPs@MgIn2S4-graphene. The photocurrent decreased with the increase of kanamycin concentration. The linear range of kanamycin was 1.0 pM-10 mu M, and the detection limit was 1.7 pM. In addition, the method can be used for the determination of kanamycin in milk and honey. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A signal-off photoelectrochemical aptasensor based on p-n type semiconductor was constructed for the determination of kanamycin. The method utilized competitive quenching effect and strand displacement reaction. The sensor showed promising results for kanamycin detection in milk and honey samples.