Rapid synthesis of a hyperfluorescence 2-pyridone derivative as a fluorescent molecular sensor for picric acid

In this article, a hyperfluorescence 2-pyridone derivative (D-TPCA) has been synthesized within 5   min by the microwave-assistant heat treatment of the aqueous mixture of citric acid and 2-aminoethanethiol hydrochloride. The as-prepared D-TPCA exhibited good aqueous solubility and excellent fluorescent property with a quantum yield of 89.9%. Because the fluorescence of D-TPCA could be effectively quenched by picric acid (PA), D-TPCA could be served as a “turn-off” fluorescence sensor for PA in aqueous solution. The proposed sensing method permitted a selective and sensitive detection of PA in a linear range of 0–45   μM with a detection limit of 56.0   nM. The determination results of PA in real water samples with a recovery range of 95.4–107.3% confirmed a good analytical performance of this sensor. In addition, the possible sensing mechanism has been discussed in detail.