| The fluorescent probe is a molecular tool that utilizes a fluorescent substance as an indicator and generates fluorescence by exciting a fluorescent agent at a certain wavelength of light,and by qualitatively or quantitatively analyzing the substance to be detected by detecting the generated fluorescence.Compared with the traditional analytical method,the fluorescent probe has the advantages of high sensitivity,good selectivity,easy to use and low biological toxicity.As a member of the family of fluorescent probes,organic small molecule fluorescent probes play an important role in the detection of ions,small molecules and biomacromolecules,and are increasingly becoming an indispensable molecular tool for modern life sciences and disease diagnosis.In recent years,organic small molecule fluorescent dyes have attracted the attention of scientific research workers,and many organic small molecule probe platform come into being,such as couMarin organic small molecule fluorescent probe platform,fluorescein organic small molecule fluorescence probe platform Rhodamine organic small molecule fluorescent probe platform and so on.However,so many probe platforms are mostly single-photon excitation and single-channel emissions.The detection process has the disadvantages of light bleaching,light damage,low penetration depth and the influence of the detection environment.With the progress and development of science and technology,the demand of accuracy of the experimental results is getting higher and higher.High signal-noise ratio is a challenge for organic small molecule fluorescent probes,while single-emission of fluorescent probes is full of fatigue.The development of two-photon imaging technology and ratio technology effectively meets the above challenges.Compared with single photon,two-photon has a long-wave excitation,which effectively avoids the disadvantages of light bleaching,light damage and low penetration depth.The ratio probe has dual channel emission characteristic,giving the ratio signal,So the results are less affected by the environment and the signal output is relatively reliable.The introduction of two-photon imaging technology and ratio technology into designing of organic small molecules will largely improve the performance of traditional organic small molecule fluorescent probe.According to this,the following work is carried out:(1)Construction of an energy transfer type two photon ratio fluorescence molecular platform based on benzopyran-fluorescein hybridization.A new probe platform was constructed by molecular hybridization with benzopyran and two-photon absorption.The platform utilizes two-photon excitation to effectively compensate for the lack of single photon excitation.Benzopyran and fluorescein are used as energy donor and acceptor respectively through the fluorescence resonance energy transfer(FRET)effect between the two The ratio of the output signal,effectively reducing the detection environment on the output of the interference.(2)benzo-pyrrole-fluorescein hybridization of FRET-type small molecule two-photon fluorescence probe to selectively detect nitric acid(NO)produced by the interaction of nitric oxide(NO)and hydrogen sulfide(H2S).The end of the probe platform constructed in work 1 is linked to diphenylphosphine benzoic acid via an ester linkage to functionally modify the recognition site of HNO.The change of the fluorescence signal of the probe before and after the presence of endogenous HNO produced by the interaction of exogenous HNO or NO and H2S in complex organisms is related to the exogenous and endogenous HNO produced by the interaction of NO and H2S detection purpose.(3)benzopyran-fluorescein hybridization of FRET-type small molecule two-photon selective fluorescence probe for selective detection of hydrogen sulfide(H2Sn).At the end of the probe through the ester bond and methacryloyl chloride connected to the functional modification of H2Sn recognition sites,analysis of H2Sn before and after the probe ratio of the signal,the H2Sn reasonable detection. |
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