Design And Application Of Cysteine Fluorescent Probe Based On Acryloyl Chloride

Cysteine plays a key role in the human body.It is not only a key regulator in the process of maintaining redox balance in the body,but also participates in protein synthesis,post-transcriptional modification,and detoxification of metabolic heavy metals in the body.Abnormal cysteine concentration may lead to growth retardation,Parkinson's disease,Alzheimer's disease,cardiovascular disease and other diseases.Therefore,the detection of cysteine concentration in biological samples has important application value.Organic small molecule fluorescent probes have the advantages of excellent selectivity and sensitivity.At present,a variety of fluorescent probes for detecting cysteine have been developed.Among them,acrylate groups are the most widely used,but they have the disadvantage of poor water solubility.In this paper,based on literature research,fluorescent probes C1 and C2 were designed by opening the coumarin molecular lactone bond,and a ratiometric fluorescent probe H1 was designed by introducing bromine substitution in the benzothiazole molecule,and studied the detection ability of fluorescent probe for cysteine.Probe C1 can complete the reaction with cysteine within 30 minutes,but it needs to be dissolved in 10% acetonitrile in phosphate buffer.Probe C2 replaces the hydrophobic ethyl ester in the molecule of probe C1 with a hydrophilic cyano group,significantly improving water solubility.Probe C2 can selectively recognize cysteine in 1 % acetonitrile buffered salt solution,and detection limit as low as 10 nM.The ratiometric probe H1 can complete the selective reaction with cysteine in 15 minutes,and the ratiometric fluorescence intensity is highly linearly related to the cysteine concentration.Among them,probe C2 has good water solubility,sensitivity and selectivity,and probe H1 has high selectivity and fast reaction speed.The development of these two probes has good application potential for the detection of cysteine in biological samples,and provides new ideas for the design of fluorescent probes.