AIEgen-based porous organic polymer-Ag nanoparticles hybrids with coreaction accelerator amplification and covalent rigidification-enhanced electrochemiluminescence for aflatoxin M1 detection.

Developing new high-performance electrochemiluminescence (ECL) emitters is a continuous hotspot. Herein, a novel AgNP-decorated porous organic polymer (AgNPs@ETTBC-BPyDAN-POP, BPyDAN = 2,2'-([2,2'-bipyridine]-5,5'-diyl)diacetonitrile) nanocomposite with coreaction accelerator amplification and covalent rigidification-enhanced ECL was prepared. AgNPs@ETTBC-BPyDAN-POP nanocomposite exhibited excellent ECL performance, not only because abundant AIE-active 4',4″',4″″',4″″″'-(ethene-1,1,2,2-tetrayl)tetrakis(([1,1'-biphenyl]-4-carbaldehyde)) (ETTBC) luminogens were covalently assembled and rigidified into ETTBC-BPyDAN-POP network, which diminished radiationless transition, but also because AgNPs functioned as coreaction accelerators that expedited the generation of coreactant radicals, which in-situ react with adjacent ETTBC+ intermediates, thereby producing more ETTBC⁎ excited states for significantly enhancing the ECL emission. Considering the eminent ECL performance, AgNPs@ETTBC-BPyDAN-POP was employed as an ECL indicator to fabricate a supersensitive biosensor for detecting aflatoxin M1, showing a wide response range (5 fg/mL - 500 ng/mL) with a detection limit of 0.57 fg/mL. Overall, this study offered a promising dual-enhancement strategy to boost AIEgens' ECL emission, thereby providing significant inspiration to develop high-efficiency AIEgen-based ECL materials for fabricating hypersensitive ECL biosensors.