Tetraphenylenthene-Based Conjugated Microporous Polymer for Aggregation-Induced Electrochemiluminescence

We demonstrate the aggregation-induced electrochemiluminescence (AIECL) generated by 1,1,2,2-tetrakis(4-bromophenyl)ethane (TBPE)-based conjugated microporous polymers (TBPE-CMPs) and its biosensing application. We synthesized three TBPE-CMPs (i.e., TBPE-CMP-1, -2, -3) using three different molecules including tris(4-ethynylphenyl)amine (TEPA), 4,4'-diethynylbiphenyl (DEP), and 2,4,6-tris(4-ethynylphenyl)-1,3,5-triazine (TEPT). The TBPE-CMPs can act as electrochemiluminescence (ECL) emitters to generate AIECL. Among them, TBPE-CMP-1 exhibits the highest ECL efficiency (1.72%) due to the improved electron-hole recombination efficiency and efficient suppression of nonradiative transition. Moreover, the ECL properties of TBPE-CMPs can be tuned by the introduction of different conjugated molecules that can decrease the energy gap to facilitate the injection of an electron into the conjugated polymer backbone. Importantly, TBPE-CMP-1 can be used to construct an ECL sensor for the detection of dopamine, whose electro-oxidation products (e.g., leucodopaminechrome (LDC), dopaminechrome (DC), 5,6-dihydroxyindole (DHI), and 5,6-indolequinone (IDQ)) may function as energy acceptors to quench the ECL emission of TBPE-CMP-1. This ECL sensor exhibits high sensitivity and good anti-interference capability against ascorbic acid and uric acid.