Design,Synthesis And Application Of Fluorescence Probe Of Cysteine Excited By Near-infrared Light

As a kind of amino acid containing sulfhydryl group,cysteine plays an important role in the physiological process.It is involved in the regulation of redox,the signal transmission and the normal apoptosis in the cells.However,the abnormal content of cysteine can cause a series of diseases,such as liver injury,Alzheimer's disease,cardiovascular and cerebrovascular diseases.In recent years,research on cysteine has attracted extensive attention.The development of highly efficient,highly selective and highly sensitive detection methods for cysteine is of great importance for the further study on molecular mechanism of cysteine in vivo.Among many detection methods,fluorescence analysis has the advantages of high sensitivity,high selectivity,simple operation and low cost,and it can be applied in cells,in situ imaging,real-time and quantitative detection of biomolecules.However,the emission wavelengths of the most reported fluorescence probes were less than 600 nm,which limits their application in detection and imaging of cysteine in vivo.In view of the above problems,this paper will develop following two aspects of researching:(1)A two-photon fluorescence probe ACP for the detection of cysteine was constructed with the dye as the fluorescent group and acrylate as the recognition group based on the previously reported two-photon dye ACF with a large two-photon absorption cross-section and an emission wavelength of near-infrared.The probe ACP was used to detect and image the cysteine in cells and deep tissues,and cysteine was visually detected in LPS-induced inflammatory model.The experimental results showed that our probe has high sensitivity(detection limit is 24.1nM)and excellent selectivity.(2)Near-infrared fluorescent dye TCF-CS was firstly designed and synthesized.Compared with Changsha dye,the absorption and emission wavelengths of TCF-CS had red shift to some extent,exhibiting good stability and high fluorescence quantum yield.Secondly,TCF-CS-Probe was designed and synthesized based on the dye platform.The probe had high selectivity and sensitivity,and the response time to cysteine are 22 times faster.The probe was also successfully applied in the detection and imaging of cysteine in vivo.