Block copolymer self-assembly mediated aggregation induced emission for selective recognition of picric acid

Abstract

Benefiting from the excellent hydrophobic properties of polystyrene and (2-(4-vinylphenyl)ethene-1,1,2-triyl) tribenzene (PS-b-PTPEE) unit a diblock copolymer is prepared to show higher aggregation induced emission (AIE). The TPE grafted block copolymer forms homogeneous solution in common organic solvents such as THF. In aqueous solution, the copolymer self-assemble to form aggregates of nanosize. The aggregates display maximum photoluminescence (PL) in a THF/water (3:7 v/v) mixture. Fortunate introduction of TPE units into block copolymer chain makes it highly sensitive probe for picric acid (an explosive amterial) via aggregation induced emission. The nitroaromatic compound of PA was effectively quenched by possible π-π interactions between TPE units of PS-b-PTPEE and hydroxyl containing phenolic acid. The quenching efficiency significantly increased nonlinearly at higher quencher concentration. The present study offers details for design and synthesis of new hyperbranched polymeric fluorescent vesicle probe with high sensitivity.