Synthesis And Application Of Several Novel Fluorescent Probes For Hydrazine Hydrate And Cysteine

Molecular probe is a tool that converts intermolecular interactions into optical signals and transmits them to the outside world,which plays a vital role in environmental sample testing,food sample analysis,biomolecular labeling,biomedical testing and imaging.Due to its excellent selectivity,high sensitivity and easy operation,it has attracted the interest of researchers in recent years.In order to perform more accurate detection of small molecule in complex sample,it is necessary to develop new fluorescent probes.In this paper,three small-molecule fluorescent probes were designed and synthesized to detect hydrazine hydrate in environmental samples,hydrazine hydrate in biological cells,and cysteine in human serum.The details are as follows:(1)A reactive hydrazine hydrate fluorescent probe based on malononitrile as recognition group was designed and synthesized.The probe has a large Stokes shift,and can detect hydrazine hydrate by fluorescence recovery after reaction with hydrazine hydrate.Considering the basicity of hydrazine hydrate,the probe can respond well to hydrazine hydrate under alkaline conditions,which has good selectivity and anti-interference ability.The detection of hydrazine hydrate has a wide linear range(0~600 ?M),and low detection limit(3.1 ppb).Thus,the probe was successfully applied to the detection of hydrazine hydrate in the actual water sample,and good results were obtained.(2)Based on the previous research,in order to achieve the detection of hydrazine in cells,a biocompatible hydrazine hydrate fluorescent probe was designed and synthesized to realize the visual detection of hydrazine hydrate with colorimetric and fluorescent dual signals.The probe utilizes an ?,? unsaturated carbonyl group as recognition group,undergoing 1,4 addition with hydrazine hydrate to restore fluorescence of the probe molecule.The detection of hydrazine hydrate has good selectivity,anti-interference ability and high sensitivity.The minimum detection limit is 1.25 ppb,which is far lower than the 10 ppb specified by the EPA.Due to good biocompatibility of probe,this probe was used to image the hydrazine hydrate in human normal liver cells,which provides new possibilities for further application of the probe.(3)A highly selective colorimetric dual-signal probe 3 was designed and synthesized for the detection of cysteine,the probe solution showed turn-on fluorescence at 440 nm after the addition of cysteine,while the color of the solution changed.Importantly,probes can specifically detect cysteine in the presence of homocysteine,glutathione and other biothiols,and the probe has been successfully used in cysteine in serum.