Enhanced superquenching of the hyperbranched conjugated polymer for the detection of nitroaromatic explosives

Carbazole-based linear conjugated polymer (P 1 ) and hyperbranched conjugated polymer (P 2 ), were successfully synthesized with high molecular weights and good solubilities through Sonogashira coupling reactions. Compared with P 1 , the charactyeristics of P 2 were remarkably changed by exhibiting outstanding thermal stabilities and different emission behaviors. In this work, a superquenching effect was observed in the TNT-detection process by using P 2. The calculated Stern-Volmer quenching constant revealed that P 2 was more sensitive than P 1 towards TNT in solution, owing to the hyperbranched structure of P 2 had multiple exciton migration channels and diffusion pathways via numerous branches in the two-dimensional (2D) space. Simultaneously, quenching efficiency of P 2 was higher than that of P 1 , due to hyperbranched structure of P 2 had multiple exciton migration channels.