Design,Synthesis And Application Of Responsive Fluorescent Probe Based On Hemicyanine Dye

Fluorescent probes are widely used in analytical and detection chemistry due to their high sensitivity,accuracy,and simplicity of operation.However,there are still some problems,such as insignificant absorption spectrum change,short emission wavelength and insignificant color change before and after the response.Hemicyanine are widely used because of their high molar extinction coefficient,good water solubility and good chemical modification.Therefore,the structure design of hemicyanine,using the change of πconjugate structure,provides a solution to achieve better detection effect in this paper.The specific research contents are as follows:1.A fluorescent probe based on hemicyanine dye for mercury ions detection.We design and synthesize a hemicyanine fluorescent probe with thiobenzoic acid as the recognition receptor,which is sensitive and specific for the detection of mercury ions by using π conjugated structure rearrangement mechanism.After the desulfurization reaction with mercury ion,responding group was removed and rearranged,leading to a large change in absorption spectra(137 nm)and a significant color change from yellow to red before and after the response.The probe has good specificity,anti-interference and fast response time.In addition,probe is used for the detection of actual water samples,and made into a portable test sheet for the detection of water samples;At the same time,it has low toxicity and is used for cell imaging.2.A novel fluorescent probe based on hemicyanine dye for p H and hypochlorous acid detection.We design and synthesize a novel near infrared fluorescent probe based on hemicyanine,which can detect p H and hypochlorous acid by destroying its π conjugated structure during response.By modifying bromine atoms with heavy atom effect on indole hemicyanine and introducing less electronegative oxygen-containing molecules,the more redshift of the spectra is achieved,and the absorption reaches near infrared region(890 nm).Under the response of p H and hypochlorous acid,absorption peak shift(365 nm)and obvious color change was observed.