A photoelectrochemical aptasensor for tetracycline based on the self-assembly of 2D MoS₂ on a 3D ZnO/Au/ITO electrode

Two-dimensional (2D) layered MoS₂ has good dispersion and adsorption properties, but being a narrow bandgap semiconductor limits its application in photoelectric sensing. In this study, a homogeneous photoelectrochemical sensor based on three-dimensional (3D) ZnO/Au/2D MoS₂ is proposed for the ultrasensitive detection of tetracycline (TET). MoS₂ is uniformly embedded on the 3D ZnO/Au surface by ordered self-assembly. The physical method of π–π interaction of MoS₂ replaces the conventional use of chemically modifying aptamers on the electrode material surface. Under optimal conditions, this method has been successfully applied to the detection of TET in milk, honey, pig kidney and pork samples with reliable results. We believe that this study presents a method for the preparation of sensing carriers and target detection with great potential for application.