A sensitive electrochemiluminescent immunosensor based on 3D-flower-like MoS2 microspheres and using AuPt nanoparticles for signal amplification

Abstract

We herein report the synthesis of MoS₂, consisting of three-dimensional flower-like microspheres assembled by bent flakes with a thickness of several nanometers. The diameter of theses spheres was approximately 1.5 μm, and they showed good catalysis of H₂O₂ and could increase the electrochemiluminescence (ECL) intensity of luminol. The ECL properties of luminol were investigated and a type of luminol composite (MoS₂–luminol) was prepared. Glucose oxidase–AuPt nanoparticles (GOx–AuPt) showed excellent catalytic performance for the reduction reaction of glucose. The prepared GOx–AuPt and MoS₂–luminol were applied in a sandwich-type ECL immunosensor for prostate-specific antigen (PSA). In the immunosensor, MoS₂–luminol acted as a solid support for PSA primary antibody, and GOx–AuPt was employed as a support for PSA secondary antibody. With the addition of glucose, hydrogen peroxide was prepared and the ECL properties of the MoS₂–luminol were enhanced. The proposed immunosensor enabled PSA concentrations to be determined in the range of 0.001 ng mL⁻¹ to 100 ng mL⁻¹, with a detection limit of 0.28 pg mL⁻¹. The experimental results indicated that the immunosensor exhibited simple instrumentation, high sensitivity, wide linear range and excellent analytical performance, and could be a promising technique for tumor marker detection.