Rational design of ZnIn2S4/CdIn2S4/CdS with hollow heterostructure for the sensitive determination of carbohydrate antigen 19-9

Complex hollow nanomaterials with multicomponent heterostructures hold significant application potential in photoelectrochemical fields. Herein, a novel hollow ternary-component ZnIn2S4/CdIn2S4/CdS heterostructure (ZIS/CIS/CdS-HHOC) was designed and synthesized via a succinct self-templated solvothermal method. The underlying mechanism of microstructure growth and enhanced electronic kinetics of ZIS/CIS/CdS-HHOC were specified. Moreover, the photoelectric conversion capacity of ZIS/CIS/CdS-HHOC was superior to that of the disordered ZIS/CIS/CdS heterojunction. As evidenced by experiments, the hollow structure of ZIS/CIS/CdS-HHOC can enhance light utilization, accelerate the transfer of charge carriers in heterojunction materials/electrolyte interfaces, and thus improve photoelectric conversion. Owing to the excellent photoelectric property of ZIS/CIS/CdS-HHOC, the fabricated label-free biosensor exhibited a high sensitivity for the carbohydrate antigen 19–9 (CA19–9) biomarker with a linear response range of 0.001–10 U·mL−1 and an ultralow detection limit of 0.76 mU·mL−1. This novel strategy of constructing multi-component nanomaterials with hollow heterostructures can be further applied to the design of other superior nanomaterials for use in photoelectrochemical fields.