Photothermal amplified cathodic ZnO quantum dots/Ru(bpy)32+/S2O82- ternary system for ultrasensitive electrochemiluminescence detection of thyroglobulin

Herein, an ultrasensitive electrochemiluminescence (ECL) immunosensor based on a high performance probe of Nb 2 CTx MXene immobilized ZnO quantum dots (QDs) was constructed for Thyroglobulin (Tg) detection. ZnO QDs with good biocompatibility and catalytic property was for the first time utilized as coreaction accelerator in Ru(bpy) 3 2+ /S 2 O 8 2− system and enhanced ECL signal. Specifically, ZnO QDs can facilitate S 2 O 8 2− reduction to generate more SO 4 − , and then reacted with cathodic radical of Ru(bpy) 3 2+ , realizing 2-fold enhancement in ECL intensity. Additionally, Nb 2 CTx MXene possesses excellent properties and was used as prominent supporter, improving the loading capacity of Ru(bpy) 3 2+ and ZnO QDs, and accelerating the electron transfer, resulting in ECL signal enhancement. Furthermore, Nb 2 CTx MXene acted as temperature controller and increased the electrode surface temperature by converting laser energy into heat, further amplified ECL signal. Because of the high sensitivity, good specificity and favorable stability, the proposed immunosensor realized sensitive detection of Thyroglobulin and had a great application prospect in bioanalysis and clinical diagnosis.