Construction Of Solid-state Fluorescent Probes Based On HPQ And Its Application In Biological Detection

It is well known that fluorescent probes are valuable tools because of their high spatial,temporal resolution,rapid analysis capabilities,non-destructive imaging capabilities,and their excellent sensitivity in biological samples.The excellent resolution and other advantages make they own amazing application value and attractiveness.In this article,we constructed three fluorescent probes to extend the wavelength of the solid-state fluorophore 2-(2-hydroxyphenyl)-4(3H)-quinazolinone(HPQ).Meanwhile,these probes have been successfully applied in fluorescence imaging and quantitative detection of carbon monoxide(CO)and cysteine(Cys),and successfully applied to the fluorescence imaging of actual biological samples.1.A new fluorescent probe(HPQ-BI-CO)based on a new solid fluorophore HPQ dye was designed and synthesized for the detection of carbon monoxide(CO)in cells and biological samples firstly.The introduction of the benzindole group in the probe extends the wavelength of HPQ,so it has the characteristics of long excitation wavelength and long emission wavelength,high selectivity,high sensitivity,and fast response capability.Encouraged by these excellent properties,the probe HPQ-BI-CO can be applied to the visualization of CO in different degrees in biological systems(such as 4T1 cells and zebrafish).2.In order to extend the wavelength of HPQ and retain its solid-state luminescence properties,we improved the synthesis method by changing the benzene indole group into another group,1-ethyl-2-methylquinoline.So as to synthesize another fluorescent probe HKPQ-CO which can detect CO,and the probe can release a new solid fluorescent dye,HKPQ.We found that the probe can be used for fluorescence imaging in situ and CO detection in Hep G2 cells and zebrafish.In addition,the probe was able to monitor CO upregulation in Hep G2 cells during hepatotoxicity under drug-induced liver injury(DILI),and was able to image the fluorescence of DILI-induced CO changes in the liver of zebrafish,thus demonstrating that the probe can be used as an analytical tool in DILI.3.Based on the previous chapter,we found that the new solid-state fluorophore HKPQ has good performance.It has a longer wavelength(650 nm)and can be used for detection in biological samples in-situ.Therefore,we modified a cysteine(Cys)recognition group on the basis of this dye,and synthesize another fluorescent probe,HKPQ-Cys,for in situ imaging and detection of Cys in cells.Through the study results,we found that the probe,HKPQ-Cys,could be successfully applied for the detection of Cys level in 4T1 cells in situ.