Zirconium based metal-organic frameworks with aggregation-induced electrochemiluminescence for sensitive analysis of aflatoxin B1 by signal dual-amplification strategy

Herein, zirconium-based metal-organic framework (Zr-TCPB), serving as an aggregation-induced electrochemiluminescence (AIECL) emitter, was successfully synthesized. Specifically, the AIE molecule 1,2,4,5- tetrakis (4-carboxyphenyl) benzene (H4TCPB), which served as the organic ligand, was systematically assembled with the metal ligand Zr to form a stable framework. The framework architecture of Zr-TCPB limited the restriction of intramolecular motions (RIM) of H4TCPB, enhancing its ECL performance. Additionally, the high specific surface area and porosity of the MOFs provided increased electrochemical active sites. Consequently, we proposed a novel AIECL biosensor using Zr-TCPB as the emitter for the sensitive detection of aflatoxin B1 (AFB1), incorporating a signal dual-amplification strategy. Among them, Ag NPs were employed as coreaction accelerators to catalyze K2S2O8, generating more SO4 center dot- and thereby amplifying the ECL signals. Furthermore, the cDNA released through the magnetic separation technique initiated the DNA strand replacement reaction (SDR), achieving signal dual-amplification The biosensor exhibited a wide linear range from 0.001 ng/mL to 100 ng/mL with a low detection limit of 0.79 pg/mL. The proposed method presented a promising approach for the ultrasensitive determination of AFB1, while offering new possibilities to enhance the application capacity of AIECL MOFs and SDR in biosensors.