Design,Synthesis And Application Of Novel Lactam-fused Aza-BODIPY Fluorescent Probes

Recently,fluorescent probes have been widely applied in various fields such as: ion detection;food analysis;small reactive biomolecules detection;discrimination of organic small molecules;cell imaging,etc.Compared with conventional fluorescent probes,the structure of the fluorescent probes is changed by irreversible or reversible chemical reaction between the probe and the analyte,and along with the break or formation of chemical bonds,the photophysical signal(absorption wavelength,emission wavelength and absorption intensity,fluorescence intensity,etc.)is changed.Reactive fluorescent probes have the advantages of lower background interference,high signal-to-noise ratio,synchronization of colorimetric and fluorescence changes,and better selectivity and sensitivity.Among them,due to large conjugated plane and long emission wavelength,the lactam-fused aza-BODIPY(abbreviation: LAB)based compounds have attracted widespread attention.In this paper,the design,synthesis and application of novel lactam-fused aza-BODIPYs were carried out.It mainly includes the following research contents:(1)A highly efficient probe has been reported based on a newly developed chromophore reaction between LAB and polyamines by virtue of unique multiple amino groups character of polyamines.This chromophore reaction includes a kinetic-controllable reaction of a B-N bond cleavage by polyamines followed by a fast hydrolysis reaction to yield much smaller conjugated molecules.With 130 nm hypsochromic shift(from 582 nm to 452 nm)of the absorption peak and up to 99% fluorescence quenching within 1 min,LAB can be used as a highly sensitive fluorescent probe for detection of polyamines solution and monitoring fish spoilage with synchronous colorimetric and fluorescent changes.(2)Based on previous work,through three-step reactions,three lactam-fused aza-BODIPY fluorescent molecules(LAB-TH4,LAB-TH6,LAB-TH8)with near-infrared emission were synthesized by replacing the benzene ring of LAB with a thiophene ring.The maximum absorption peak was located at 582 nm and the maximum emission peak was all above 650 nm.Compared to the LAB in the previous section,all three molecules produce a significant red-shift in emission and absorption.It’s found that all three molecules have the ability to generate reactive oxygen species,and can be used for cell fluorescence imaging.