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^•− 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.