The Coumarine Based Fluorescence Probe With Different Outside Charges

In this paper, we designed and synthesized four coumarin-based fluorescence probe with different outside charge:m-CPPS, m-CPPS-P, m-CPPP and m-CPM, The structure of them use the represented by NMR, ESI-MS and IR. Because of the good solubility of these probes, we can do the test in pure water system (pure PBS buffer solution, pH=7.4).The response speed of these probes for Cys, Hcy and GHS are m-CPPP> m-CPM> m-CPPS-P> m-CPPS. The detection limited of Cys for m-CP derivant are m-CPPP<m-CPM<m-CPPS-P<m-CPPS, respectively. The phenomenon is the greater electropositivity, the faster response speed and the lower detection limited (DL). To the response of the various amino acids it is important that effective molecular collision between amino acids and probes, and the effective collision depend on pKa of amino acid, steric hindrance and the charge of probe and amino acids. The pKa of pKaCys=8.30<pKaHcy=8.87<pKaGSH=9.20, steric hindrance is Cys> Hcy> GHS, respectively. The probe m-CPPP that has the greatest electropositivity have the best performance.The performance of m-CPPP for response to BSA is better than other probes.The electropositivity of probes can impress the function:faster response speed, lower DL and the stronger fluorescent.By detecting the hydrosulfite, we found that m-CPPS can selectively response to HSO3-and low DL (2.88×10-8mol/L). In the food addition m-CPPS just can response to HSO3-.There for m-CPPS can used as hydrosulfite probe to contribute to food testing.