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

The content of Hydrogen sulfide (H2S) 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-NO2, based on the hemicyanine fluorophore, was designed and synthesized for H2S detection in aquaculture. Accompanied by a noticeable color change from purple to blue, the probe X-NO2 shows strong fluorescence at 685 nm when H2S mediates the thiolysis of DNP ether and release X-OH. In 10 % DMSO-PBS (pH=7.4,10 mM,v/v), the probe X-NO2 shows high selectivity to H2S than other anions and some somebiologicalthiols, and strong anti-interference capacity. Probe X-NO2 also has short response time (within 3 min) and low detection limit (65 nM) towards H2S and has a stable performance over a wide pH range (6-9) in hydrogen sulfide monitoring system. Moreover, probe X-NO2 was used to determine the H2S levels in real water samples from aquaculture accurately and conveniently, which shows a good application prospect in the future. This work reported a near-infrared fluorescent probe X-NO2 for the detection of H2S based on the thiolysis of 2,4-dinitrophenyl that attached to a hemicyanine fluorophore. With strong fluorescence response to H2S, X-NO2 displayed high selectivity, strong anti-interference capacity, short response time, low detection limit towards H2S and stable performance over a wide pH range. X-NO2 has advantages in the rapid and convenient detection of H2S content in aquaculture water samples.image