Electrochemiluminescence evaluation for carbohydrate antigen 15-3 based on the dual-amplification of ferrocene derivative and Pt/BSA core/shell nanospheres

Herein, a novel methodology for ultrasensitive and facile breast cancer biomarker carbohydrate antigen 15-3 (CA15-3) evaluation was proposed by fabricating a sandwiched ECL immunosensor. In the protocol, MOCs-Fc and Pt@BSA-luminol nanohybrids were successfully synthesized and further employed to achieve dual-amplification strategy for luminol-H2O2 system. Notably, inherent porous microstructure and large specific surface area from MOCs enabled a high loading of Fc, which succeeded in catalyzing luminol-H2O2 ECL emission and therefore enhancing ECL response. In addition, higher sensitivity could be realized due to the excellent electronic conductivity of MOCs. Furthermore, the as-obtained Pt@BSA- luminol was not only employed as capture probe to recognize CA15-3 after hybridization with Ab2, but also played a crucial role in acting as ECL signal probe due to the presence of massive luminol. It is of vital importance that Pt@BSA core/shell nanospheres showed admirable catalytic effect towards H2O2, which resulted in more excited state luminol and stronger ECL intensity. Therefore, the synergistic amplification strategy of MOCs-Fc and Pt@BSA nanohybrids offered an extremely enhanced ECL signal. The well-established applicable ECL immune- sensing platform displayed favorable analytical performance for CA15-3. In summary, the proposed ECL immunosensor opened a new era for sensitive CA15-3 evaluation and offered a promising platform for clinical breast cancer diagnostics.