Carbon dots and gold nanoparticles doped metal-organic frameworks as high-efficiency ECL emitters for monitoring of cell apoptosis

• A novel high-efficiency ECL emitters of CDots@ZIF-8/AuNPs were synthesized. • The ECL intensity of CDots@ZIF-8/AuNPs showed 7-fold enhancement. • The ECL biosensor monitoring of caspase-3 activity was fabricated. Synthesis of highly efficient, cost-effective, Easy labeling electrochemiluminescence (ECL) luminescent materials is attractive in developing highly sensitive ECL sensors for many applications such as clinical diagnostics, biosecurity, and environmental monitoring. Herein, by doping carbon dots (CDots) and gold nanoparticles (AuNPs) into zeolitic imidazolate framework (ZIF-8), novel high-efficiency ECL emitters CDots@ZIF-8/AuNPs nanocomposites were prepared. Our experiment indicated that ZIF-8 in the nanocomposites not only act as carrier for ECL labels, but as an ECL accelerator to convert the CDots to CDots •– , causing the enhanced ECL intensity of CDots in K 2 S 2 O 8 solution. AuNPs, which have excellent conductivity, were formed in the pores of ZIF-8 to further enhance the ECL signals. As a result, the nanocomposites showed a final about 7-fold ECL intensity as compared to the pure CDots. AuNPs in the nanocomposites could also provide a platform for effective attaching the biomolecular, making the nanocomposites ideally suited for building biosensor. As a proof of concept, the prepared CDots@ZIF-8/AuNPs was successfully applied in the rapid and simple ECL monitoring of caspase-3 activity during cell apoptosis, which gives impetus to the design of new ECL luminescent materials with ultimate applications in highly sensitive bioanalysis.