Preparation Of Indanone-Based Fluorescent Probes Materials And Their Application For Biomercaptan Recognition

Biomercaptans mainly include glutathione(GSH),cysteine(Cys)and homocysteine(Hcy).They play an prominent role in medicine,pharmacology and life system,and are intimately related to human life activities.These biomercaptans could maintain normal physiological functions and cell metabolism,andthe imbalance of them in body could lead to a series of diseases.Therefore,it is of great significance to study the distribution and concentration change of biological mercaptan.Compared with the traditional biological mercaptan detection methods,fluorescence probes have caused a great deal of attention because of their advantages including simple operation,high sensitivity,high spatiotemporal resolution and real-time in-situ detection.In this thesis,the fluorescent probe materials based on indanone were designed and prepared.The main research was concluded as follows:1.In the first part,the indoline structure was introduced as the electron donor,and the acrylate group was used as the recognition group to prepare ICT fluorescent probes.By changing the electron-withdrawing ability of acceptor in the fluorescent probe,we obtained two probes INIAc-CN(dicyano as acceptor)and INIAc-O(carbonyl as acceptor)for biological mercaptans.The results exhibit that INAc-CN has longer emission(625 nm)and stronger recognition for Cys and Hcy.The LOD of INIAC-CN for Cys/Hcy can reach to 1.92 and 3.46 μM,respectively.Meanwhile,the probe has low toxicity and good biocompatibility,and have been successfully applied for imaging Cys/Hcy in cells.The reason for this difference is that the introduction of dicyano groups can effectively enhance the intramolecular ICT effect and reaction activity of these fluorescent probes,thereby exhibiting longer emission wavelengths and high detection sensitivity.2.In the second part,considering the recognition specificity and small Stokes shift may affect further application of probe,thus,we constructed an ESIPT fluorescent probe HBT-IDAc with large Stokes shift.The probe was prepared from indanone and the typical ESIPT hydroxyphenylbenzothiazole(HBT),and introduced the diethylene glycol monomethyl ether group to improve its water-solubility.The results indicate that HBT-IDAc can specifically identify Cys with Stokes shift to 210 nm and LOD to 0.89μM.And the probe can also be used to specifically identify Cys in cells.At the same time,in order to compare the influence of the differences in the structural positions of phenolic hydroxyl groups and benzothiazole on the optical properties of the probe,we synthesized an ICT type fluorescent probe p-HBT-IDAc.The experimental results showed that compared to ICT type fluorescent probes,ESIPT type fluorescent probes have better optical properties.3.In the third part,in order to overcome the aggregation-caused quenching(ACQ)effect of the above fluorescent probes,we used the aggregation-induced emission(AIE)active fluorophore(2-(2-hydroxyphenyl)-4(3H)-quinazolinone)(HPQ)and indanone to prepare the fluorescent probe HPQ-ID.The results indicate that the probe can selectively recognized Cys and NaHS in the solvent system of PBS/DMSO(95%).This chapter provides researchers with new ideas for structural design in addressing molecular solubility.