A dual mode immunosensing platform constructed on CdIn2S4 near-infrared electrochemiluminescence emitter and AuNPs@g-C3N4 for zearalenone sensing

In this study, a near-infrared (NIR) electrochemiluminescence (ECL) emitter CdIn 2 S 4 was synthesized by a convenient hydrothermal strategy. The ECL properties of the obtained CdIn 2 S 4 were examined in the presence of potassium persulfate coreactant at an excitation potential of − 1.25 V. The low trigger voltage of CdIn 2 S 4 may be ascribed to its lower bandgap. This lower excitation potential could effectively reduce the side-effects induced by high voltages, while maintaining the biological activity of antibodides and antigens. The ECL features of CdIn 2 S 4 were also investigated, demonstrating that CdIn 2 S 4 exhibited excellent NIR characteristics, and surface state transitions led to the ECL emission. Importantly, CdIn 2 S 4 was introduced into ECL and electrochemical impedance spectroscopy (EIS) to establish a dual-mode immunosensing interface. Meanwhile, AuNPs@g-C 3 N 4 with excellent properties were used to promote electron transmission and increase the immobilization amount of zearalenone (ZEA) antibodies in the dual-mode sensing system. The developed immunosensing strategy displayed superior sensing performance in ZEA analysis. The detection limits of ZEA were 30 fg mL −1 (ECL model) and 10 fg mL −1 (EIS model), respectively. The desirable recovery results of ZEA in corn samples prove the application potential of the NIR emitter CdIn 2 S 4 in developing a dual-mode immunosensing system for early real-time use.