One-step electrochemiluminescence immunoassay for breast cancer biomarker CA 15-3 based on Ru(bpy)62+-coated UiO-66-NH2 metal-organic framework

By virtue of the metal organic framework UiO-66-NH 2, an ingenious electrochemiluminescence immunosensor was successfully constructed for subtle exploration of the breast cancer biomarker CA 15-3. In this protocol, Ru(bpy) 3 Cl 2 ·6H 2 O (Ru(bpy) 3 2+ ), as a conventional luminescent reagent, provides a stable and strong luminescent signal. The UiO-66-NH 2 serves as a carrier to provide a large specific surface area for enhancing the electrochemical luminescence signal response of Ru(bpy) 3 2+ . UiO-66-NH 2 , Ru(bpy) 3 2+ are fixed together with Nafion membrane, and CA 15-3 antibody is covalently conjugated onto the membrane through the amide reaction. Ru(bpy) 3 2+ @UiO-66-NH 2 is used as the detection system. The experimental results reveal that the ECL signal decreased obviously after the CA 15-3 antigen molecule is captured on the immunosensor, with the capture of manifesting the principle of electrochemical luminescence quenching detection. Under optimal conditions, the sensor is sensitive and selective for detecting CA 15-3 with the detection range from 5 × 10 −4 to 5 × 10 2 U mL -1 and the low LOD (1.7705 × 10 -5 U mL -1 ). Furthermore, multiple experiments elucidate that the as-prepared sensor could be used for susceptibly detect CA 15-3 in actual samples, which has underlying application prospects in biological analysis.