Design And Spectra Study Of Fluorescent Probes For H₂S And HClO

Fluorescent probe is a method which processes advantages including good visual performance, low detection limit and so on. Small molecule organic fluorescent molecular probes, such as BODIPY, rhodamine, fluorescein and coumarin, have been successfully employed in biosensing, environmental detection, disease diagnosis and therapeutic, as well as relative areas, and play important role in these areas. Therefore, fluorescent probes based on coumarin and rhodamine have drawn widespread attention.In this paper, we have designed and synthesized a novel coumarins based hydrogen sulfide (H2S) fluorescent molecular probe 2-1. The probe 2-1 exhibited a rapid and selective response to H2S in PBS buffer (50 mM, pH 7.4, containing 30% CH3CN,V/V). In the presence of H2S, the fluorescence intensity of probe 2-1 was increased significantely. When the concentration of H2S changes from 0 to 20 μM, the linear detection can be obtained with a correlation coefficient of 0.9989. It is worth mentioning that, H2S and sulfur dioxide (SO2) both could be recognized by probe 2-1 in the investigation of UV-visible absorption spectrum. However, probe 2-1 only selective response to H2S in the study of the fluorescence emission spectra. Combined with UV-visible absorption spectra, fluorescence emission spectra,]H NMR and HRMS, we confirmed that this could mainly ascribed to the different reaction mechanism between the probe 2-1 and H2S, SO2.This article also synthesized the hypochlorous sensor 3-4 based on the rhodamine B and naphthalimide. The fluorescent molecular probe is designed and synthesized based on FRET. It possesses high energy transfer efficiency and excellent photochemical properties. The rhodamine B-naphthalimide sensor 3-4 could identify hypochlorous effectively acid in PBS (50 mM, pH 7.4, containing 30% CH3CN,V/V) buffer solution.When the concentration of the main body is 5μM, a good linear relationship from 0 to 50×10-5 M could be obtained between fluorescence ratio and the concentration of hypochlorous acid.