Electrochemiluminescence Platforms Based on Small Water-Insoluble Organic Molecules for Ultrasensitive Aqueous-Phase Detection.

Highly efficient detection in the aqueous phase for water-insoluble organic molecule probes is challenging. The bright aggregated-state electrochemiluminescence (ECL) of 1,1-disubstituted 2,3,4,5-tetraphenylsiloles by a co-reactant approach was discovered, and a heterogeneous aggregation-induced emission ECL (HAIE-ECL) was constructed at the electrode surface, showing very high ECL efficiency (37.8 %) and selective recognition for industrially important DNBP plasticizer with a low detection limit of 0.15 nm in the water phase. A mechanistic study indicates that ECL is mainly generated due to the high electron affinity of siloles and restriction of the intramolecular motions caused by their propeller-like noncoplanar structures. This system realizes the sensing of organic-based ECL in the water phase by solving the crucial problems of water insolubility and aggregation-caused quenching (ACQ), and demonstrates potential for further application because of its design and high efficiency.