Unveiling the Transformation from Aggregation-Caused Quenching to Encapsulation-Induced Emission Enhancement for Improving the Photoluminescence Properties and Detection Performance of Conjugated Polymer Material in Multiple States

Abstract

High hydrophobicity of π-extended conjugated polymers (CPs) adversely affects their photoluminescence quantum yield (PLQY) in water and hydrogel/solid state via an unsolicited aggregation-caused quenching (ACQ) process which ultimately hampers their sensing and imaging performance. Herein, an efficient strategy is presented to suppress and transform such ACQ process into an encapsulation-induced emission enhancement (EIEE) effect through facile preparation of CP/Pluronic F-127 fluorescent hybrid micelles and hydrogel. As a proof-of-concept, successful encapsulation of polyfluorene derivative PF-DBT-Im into F-127 micelles not only displays an improved PLQY (≈200% increment) in water/hydrogel state but also delivers unique and augmented sensing responses toward the emerging pollutants tetracyclines taken as model analyte, validating the superiority of EIEE-active hybrid micellar systems over ACQ suffering PF-DBT-Im aggregates. The established method not only provides a facile solution to circumvent ACQ problem existing in low water dispersible CPs but also endorses an enhanced, simplified sensing system for visual and on-site detection of analytes with likely futuristic applications in biomedicine and solid-state optoelectronics.Encapsulation-induced emission enhancement (EIEE) is proposed as a new concept to circumvent the aggregation-caused quenching (ACQ) problem, improve photoluminescence quantum yield (PLQY), and augment detection performance of conjugated polymer material. As a proof-of-concept, successful encapsulation of the conjugated polymer PF-DBT-Im into F-127 micelles displays an improved PLQY (≈200% increment) in water/hydrogel state and facilitates augmented sensing response toward tetracyclines.