The Design Of Fluorescent Probe Based On Dimer-rhodamine Derivatives

The content of various anion,cation,amino acids and proteins in organisms plays an important role in the maintenance of life and health.If the distribution and concentration of these substances in organisms can be easily detected,it will play a very important role in the prevention and control of the diseases they can cause.Therefore,the development of rapid,accurate,non-destructive,in situ detection of these substances analysis methods have become the focus of researchers' attention.Small molecule fluorescence probe technology,as a new analytical and detection technology,has attracted the attention of many researchers and developed into an independent analytical technique because of its sensitive,high accuracy,low detection limit and its ability to be used in fluorescent imaging of organisms.Rhodamine is a common biological fluorescence dyes with many excellent optical properties,such as: larger molar absorption coefficient and fluorescence quantum yield,better photo stability and so on.Therefore,rhodamine is often used as a fluorescent matrix in the design of fluorescent probes.Because fluorescent probes based on rhodamine derivatives contain inherent xanthene,the wavelength of absorption and emitting varies little,the wavelength of absorption is usually near 550 nm,and the wavelength of emitting is usually near 570 nm.However,when fluorescent probes are used in biological imaging,the large absorption wavelength can effectively reduce the effect of biological spontaneous light and improve the signal-to-noise ratio.Theoretically,an extended conjugate structure can make the absorption wavelength of a fluorescent probe shift to red.Based on this,On the basis of the predecessors,this paper designs and develops a pair of fluorescent probes based on dimer rhodamine derivatives,which are a pair of cis and trans isomers,the fluorophore of them are dimer-oxanthone.The experimental data show that there are great differences in the photophysical and photochemical properties of the isomers,the trans fluorescence probe shows a good selectivity to palladium ions,and as the fluorescent probe has a larger rigid plane fluorophore,which makes the maximum absorption wavelength red shift,reaching 603 nm,The position of the fluorescence emission peak reaches 625 nm,and the position of the absorption and emission peaks of the normal rhodamine is about a red shift of about50 nm.