The Fluorescence Properties And Application In Fluorescence Imaging Of Rhodamine Derivatives

Fluorescent probes have the advantages of fast response,good selectivity,simple operation and low cost,and plays an important role in biologic imaging technology.Rhodamine fluorescent probe has excellent photophysical property,such as high fluorescence quantum yield,large absorption coefficient,long emission wavelength and little interference of background fluorescence.In addition,rhodamine dyes have the advantages of cheap,low toxicity,high water solubility,pH-insensitive,and so on,which makes it one of the most important precursors to synthesize fluorescent probes.Therefore,it is very important to design and synthesize excellent rhodamine probe.In this paper,a series of rhodamine and Si-rhodamine fluorescent probes with high stability were prepared by modification of rhodamine,and their fluorescence properties and fluorescence imaging were studied.The main contents and results are outlined as follows:Rhodamine probes(AZOR-1,AZOR-2,AZOR-3)and Si-rhodamine(AZSiR-1,AZSiR-2,AZSiR-3),in which the O atom at the10-position of the xanthene moiety is replaced with a SiMe2 group,were synthesized.These probes have a high absorption coefficient(105 M-1cm-1).NIR Si-rhodamines(AZSiR)displayed red-shifted absorption and emission maxima(?abs = 652-664 nm and ?em = 663-681 nm)by comparison with AZOR(?abs = 553-562 nm and ?em = 580-588 nm).The bulky methy groups on 2-position of the pendant phenyl ring are beneficial to improve fluorescence quantum yield(AZOR: from 52% to 74%;AZSiR: from 24% to 74%),at the same time,the attack of the nucleophile can be prevented,so that the probe has good chemostability.Furthermore,the chemical inertness of trifluoromethyl on phenyl ring endow Si-rhodamine probes better photostability.Moreover,confocal microscopy experiments establish that AZOR and AZSiR probes have live cell permeability,low cytotoxicity and AZOR sensors can be applied to the localization of mitochondria.These probs also have good photostability in HeLa cells.