Aggregation-Induced Electrochemiluminescence Sensor Based on 3D Graphene Aerogel-Driven Functional Iridium Nanoflowers Luminophores for Selective Detection of Thiamphenicol

Thiamphenicol (TAP) is primarily used to treat bacterial infections in animals, but its residues lead to antimicrobial resistance and public health risks. This study constructed an aggregation-induced electrochemiluminescence sensor (AIECLS) by embedding iridium nanoflowers into graphene aerogel (GA) through electrostatic interactions, combined with bifunctional monomers molecularly imprinted polymers (MIPs), achieving sensitive and targeted detection of TAP. Specifically, hydrophilic iridium nanoflowers were synthesized by surfactant-assisted reprecipitation, where the cationic surfactant cetyltrimethylammonium bromide (CTAB) directed self-assembly of iridium complexes and endowed them with hydrophilicity. The long alkyl chains of CTAB facilitated the formation of iridium nanoflower aggregates, restricting movement of luminophores and reducing nonradiative energy loss. The 3D porous structure and excellent conductivity of GA provided an ideal carrier for AIE molecules and a multifunctional microreactor. Its porous structure effectively confined and enriched luminophores, while the 3D conductive network of GA accelerated electron transfer kinetics. Moreover, the AIECL enhancement effect of CTAB-Ir caused by the electrostatic interaction synergistically amplified the electrochemical luminescence intensity. The synthesized MIPs enhanced both binding capacity and affinity toward TAP through synergistic interactions of multiple complementary functional groups, achieving specific detection of TAP. The linear range of the established sensor was 1.00 × 10^-9-5.00 × 10^-5 mol L^-1 with a limit of detection of 1.85 × 10^-10 mol L^-1, and TAP recoveries in spiked experiments were 87.02-98.06%, which were consistent with high-performance liquid chromatography results. This study provides new insights into the design of AIECLS using iridium-based materials and confinement enhancement strategies while establishing a new method for monitoring hazardous substances in food.