Electrochemiluminescence Resonance Energy Transfer between Ru(bpy)32+ and CdZnSe@ZnSe Quantum Dots for Ovarian Cancer Biomarker Detection

Herein, an enhanced electrochemiluminescence resonance energy transfer (ECL-RET) from Ru(bpy)(3)(2+) to the core/shell CdZnSe@ZnSe quantum dots (CdZnSe@ZnSe QDs) was first designed for ovarian cancer biomarker analysis. The TiO2 metal-organic frameworks (TiO2 MOFs) were used as a promoter because of its unique semiconductor structure and high loading ability for Ru(bpy)(3)(2+). Additionally, the Envision complex with numerous horseradish peroxidases (HRPs) was employed to immobilize CdZnSe@ZnSe QDs, the acceptor of ECL-RET, which further improved the ECL emission of CdZnSe@ZnSe QDs. Concretely, reactive oxygen species (ROS), for instance, O-2(center dot-) and OH center dot, were first yielded due to the catalytic ability of HRP to H2O2 , followed by the electron from O-2(center dot-) or hole from OH center dot injection into the CdZnSe@ZnSe QDs, triggering an extremely strong ECL response of CdZnSe@ZnSe QDs. On the basis of all of the above features, a highly effective ECL-RET biosensor was elaborately established to detect the targets in the range from 1.00 x 10(-6) to 1.00 x 10(2) ng/mL with a low detection limit of 3.30 x 10(-1) fg/mL (S/N = 3). This work opened up a new avenue for developing high-performance ECL-RET biosensors and demonstrated the high potential of the new biomarker in clinical ovarian cancer screening.