Design,Synthesis And Biological Applications Of Various Biothiol Fluorescence Probes

The reactive sulfur species?RSS?is consist of small molecule biothiol and hydrogen sulfide?H₂S?,play an important physiological role in biological systems,such as regulating redox homestasis and cell growth.The reactive sulfur species have attracted people's attention in recent years for its close relationship with human physiological functions.A number of studies had shown that abnormal concentration of biothiols lead to variety of disease.Therefore,detection thiols and H₂S in complex biological systems is of great significance to the fields of chemistry,biology and medicine.Recently with its high selectivity and sensitivity,simple operation and good reproducibility,fluorescent probe has become an ideal tool for the detection of biothilos and hydrogen sulfide in biological systems.According to the subtle difference of chemical structures and properties of these biothiols,we designed and synthesized a series of fluorescence probes to distinguish Cys/Hcy from GSH/H₂S.Firstly,we chose CS and NBD as the fluorescence signal platform to design and synthesize a dual-channel fluorescent hybrid dyad?CS-NBD?for efficiently discriminating Cysteine?Cys?/homoCysteine?Hcy?from glutathione?GSH?/hydrogen sulfide?H₂S?.CS-NBD performs inherently no fluorescence due to the quenching effect of nitrodiazole,after responding to Cys/Hcy in aqueous solution,CS-NBD generates significant fluorescence enhancement in two distinct emission bands?Green-Red?;while encountering with GSH/H₂S,CS-NBD induces the fluorescence increase only in red channel.We tested the probe with spectral performance,cytotoxicity and zebrafish imaging application.It can be seen that CS-NBD can efficiently discriminate Cys/Hcy from GSH/H₂S,and its low limit detection and little cytotoxicity show that ti can be applied well in biological systems.We except that the probe could be a promising tool for disclosing the interrelated roles of biothiols in pathological diagnosis.Secondly,we chose HBTMC1 as the fluorescence signal platform to design and synthesize an fluorescence probe,which have three distinct emission bands can efficiently for discriminating Cysteine?Cys?/homoCysteine?Hcy?from glutathione?GSH?and hydrogen sulfide?H₂S?.Free HMN performs almost no fluorescence due to the hydroxyl is protected by NBD chromophore,while responding to Cys/Hcy in aqueous solution,HMN generates significant fluorescence enhancement in two distinct wavelength range?green-red?;when HMN responding to GSH and low concentration of hydrogen sulfide?H₂S?,HMN generates significant fluorescence enhancement in red emission;with the addition of hydrogen sulfide?H₂S?in aqueous solution,HMN generates significant fluorescence enhancement in blue emission and fluorescence reduction in red emission.We tested the probe with spectral performance and cytotoxicity.It can be seen that HMN can efficiently discriminate Cys/Hcy from GSH and H₂S,its low limit detection and little cytotoxicity show that ti can be applied well in biological systems.We hope this probe provides a promising tool for unveiling the interrelated roles of biothiols in various physiological and pathological conditions.Thirdly,we chose CF as the fluorescence signal platform to design and synthesize an new three distinct emission bands fluorescence probe for efficiently discriminating Cysteine?Cys?/homoCysteine?Hcy?from glutathione?GSH?and hydrogen sulfide?H₂S?.CNF only exhibits its intrinsic flavylium dye red emission,when CNF responding to Cys/Hcy in aqueous solution,CNF generates significant fluorescence enhancement in two distinct emission bands?bule-green?;while CNF responding to GSH,CNF generates significant fluorescence enhancement only in blue emission bands;while CNF responding to hydrogen sulfide?H₂S?,CNF generates significant fluorescence enhancement in blue emission bands and reduction in red band.We tested the probe with spectral performance,it can be seen that CNF can efficiently discriminate Cys/Hcy from GSH and H₂S,at the same time,we design a logic test and it was found that the probe could detect one or several kinds of thiols in aqueous solution.We hope that this work can provide a design strategy for constructing multiple-input fluorescent molecular logic gates.