The Research On The Self-assembly And Cell Imaging Properties Of Photoresponsive Fluorescence Dyes

Tumor seriously threat human health due to its high mortality.Up to now,surgery is still the main treatment during the oncotherapy.However,efficiently districting the pathological tissue and normal tissue is one of the most rigorous challenges in surgery operation as tissues removed more or less will affect the recovery of patients.Hence,it is necessary and urgent to develop novel methods to district the pathological tissues.With these in mind,a new activable fluorescence probe,bearing accurate imaging and high signal-to-noise ratio,has been developed in this paper,which will provide a new strategy in tumor distinction.The main contents are as follows:1.3-methylene-2-(quinolin-8-yl)isoindolin-1-one(MQIO)was designed and synthesized.Its transformation from monoclinic phase to triclinic phase was realized by non-invasive remote control of light in solution,aggregate and crystal.Thereafter,several MQIO derivatives were successfully obtained by the modification of molecules,improving their fluorescence imaging penetration,responsiveness,contrast and stability.This work will provide theoretical basis for design and synthesis of excellent fluorescence probes.2.Based on the fact that the high rotational energy barrier of the MQIO core unit can limit the molecular vibration and rotational energy loss,we synthesized a new type of twisted D-A fluorescent molecule through structural engineering design.The molecule used the TPA group as the donor,which attenuated the electron withdrawing of carbonyl to enhance the intramolecular charge transfer(ICT).The intramolecular hydrogen bond stabilized the conformation of the excited state,and the twisted structure formed by the rotation of C color N single bond in MQIO after light stimulation inhibited ?-? stacking in the solid,so it had the characteristics of dual states,high emission efficiency and minimizing quenching in polar solvents.In addition,thanked to the anti-solvent effect,the quantum yield of the molecule was not affected by the polarity of the solvent,and biological imaging can be achieved efficiently at any concentration.3.By effectively combining targeted peptides(RGD)and hydrogen-bonded peptides(KLVFF)with photoresponsive MQIO derivative M1,a photoactivated fluorescent probe M1-pep was designed and synthesized.Under the UV light,the molecular M1 rotated the Cmurn single bond,which quickly shortened the distance of the hydrogen bond in the KLVFF assembly fragment,so that the fluorescence probe was rapidly transformed from dispersed nanoparticles into a fiber network,so that it was not easy to be metabolized by the organism.At the same time,the opening of fluorescence realized the accurate imaging of diseased cells with high signal-to-noise ratio,which will provide an effective strategy for tumor resection.