Fluorescence Properties Of Chormene Derivatives And Its Application Of Bio-imaging In Living Cells

The use of fluorescent probes to specifically identify,quantify,and trace analyte in living organisms is one of the important applications of fluorescent compounds in the biological field.It is generally accepted that the ability to specificity responds to analyte and maintain stable fluorescence in the detection environment is important for fluorescent probes.Considering that the biological environment is based on an aqueous solution.Therefore,it is important to explore the solvent effect of water solvents on fluorescent compounds.For most fluorescent probes,water molecules always cause fluorescence quenching(ACQ)by the aggregation of fluorescent molecules.The presence of the ACQ effect limits the use of fluorescent compounds in the biological field.Subsequent discovery of the aggregate induced emission(AIE)effect addresses the problems encountered with ACQ-type fluorescent probes from the root cause.With the widespread use of AI E-type fluorescent probes in the biological field,its drawbacks have gradually emerged.Since AIE type probes tend to be less soluble in water,they spontaneously aggregate in the biological environment,which causes them to produce background fluorescence without acting on the substrate.The researchers modified the AIE probe by introducing a water-soluble group,which greatly improved the problem.However,the introduction of water soluble groups is often accompanied by complex synthetic steps.Therefore,it is necessary to further develop a novel fluorescent compound that can avoid background fluorescence.Here we will report a class of chromene compounds that emit intense fluorescence in high water content solvents.Using the compound CHal as a representative,we explored its fluorescent luminescence mechanism.Through experiments,we found that the formation of hydrogen bonds between the carbonyl group and the water molecule on CHal is the key to the enhancement of fluorescence intensity.We developed an off-on formaldehyde recognition probe CHFA by introducing a formaldehyde recognition group onto the chromene-based CHa3.The response of CHFA towards formaldehyde is high sensitivity,specificity and excellent pH-stability and anti-interference to formaldehyde.CHFA can effectively imaging formaldehyde in HeLa cells without background fluorescence.The successful of proves that the application of the chromene compound can aviod back ground fluorenscence and false positive problems which appears in the application of AIE-types probe in biological fields.