Novel molecularly imprinted photoelectrochemical sensor for rutin based on Bi2S3/ZnIn2S4 heterojunction

A molecularly imprinted polymer/Bi2S3/ZnIn2S4/ITO sensor was fabricated and used for the photoelectrochemical detection of rutin. The Bi2S3/ZnIn2S4 composite was synthesized by solvothermal method and it displayed good photoelectrochemical property because of the matched energy levels of Bi2S3 and ZnIn2S4. In addition, ZnIn2S4 could improve the stability of the composite and avoid photocorrosion. The photocurrent signal of the Bi2S3/ZnIn2S4 composite was much larger than that of Bi2S3 and ZnIn2S4 under visible-light irradiation. Moreover, rutin imprinted chitosan was prepared by mixing rutin and chitosan solutions, followed by simple cross-linking reaction with glutaraldehyde at room temperature. The molecularly imprinted material was combined with Bi2S3/ZnIn2S4/ITO to construct photoelectrochemical sensor, and the resulting sensor showed a low detection limit (i.e. 0.003 μM) and a wide detection range (i.e. 0.01–100.0 μM) for rutin. It also displayed high stability and selectivity. The sensor could be used for the detection of rutin in real samples.