Tetraphenylethene-based polymeric fluorescent probes for 2,4,6-trinitrophenol detection and specific lysosome labelling

Abstract A series of neutral conjugated polymers (NCPs) and conjugated polyelectrolytes (CPEs) containing tetraphenylethene (TPE) were synthesized and characterized. Due to the presence of TPE units, NCPs exhibit aggregation-induced emission characteristics and strong fluorescence in the aggregated state. NCPs can function as fluorescent probes to detect 2,4,6-trinitrophenol in aqueous media with extremely high sensitivity, low detection limit and good anti-photobleaching properties. The value of quenching constants (Ksv) is by up to 1.72 × 107 M−1 and the detection limit is as low as 5 nM. NCPs can also be made into the fluorescence test strips for the detection of 2,4,6-trinitrophenol in a practical application. The corresponding CPEs are obtained from the facile reaction of the NCPs with pyridines. The CPEs exhibit low cytotoxicity and can be used to track lysosomes in HeLa cells, which is meaningful in visualizing and understanding intracellular metabolism and various physiological processes. Based on the identical polymer skeleton, these conjugated polymers could be employed as fluorescent probes for multipurpose application.