A fast and specific near‐infrared fluorescent probe for hydrogen sulfide detection in aquaculture freshwater

Abstract The content of Hydrogen sulfide (H 2 S) is one of the most important indicators of aquaculture water quality monitoring, which has a profound impact on the survival of aquatic animals and the income of aquaculture. Therefore, it's of great significance to develop an accurate and convenient detection method for the detection of hydrogen sulfide in aquaculture. Herein, using 2,4‐dinitrophenyl (DNP) ether as the detection group, a novel near‐infrared (NIR) fluorescent probe, X‐NO 2 , based on the hemicyanine fluorophore, was designed and synthesized for H 2 S detection in aquaculture. Accompanied by a noticeable color change from purple to blue, the probe X‐NO 2 shows strong fluorescence at 685 nm when H 2 S mediates the thiolysis of DNP ether and release X‐OH. In 10 % DMSO‐PBS (pH=7.4,10 mM,v/v), the probe X‐NO 2 shows high selectivity to H 2 S than other anions and some somebiologicalthiols, and strong anti‐interference capacity. Probe X‐NO 2 also has short response time (within 3 min) and low detection limit (65 nM) towards H 2 S and has a stable performance over a wide pH range (6‐9) in hydrogen sulfide monitoring system. Moreover, probe X‐NO 2 was used to determine the H 2 S levels in real water samples from aquaculture accurately and conveniently, which shows a good application prospect in the future.