Synthesis And Biological Applications Of 9,10-distyrylanthrance Deravitaves

Fluorescent bio-probes are important tools for bio-sensing and optical imaging,which allow direct visualization of bio-analytes at the molecular level and also offer insights into complex biological structures/processes.The sensing and imaging selectivity of the bio-probe is mainly determined by interactions between bio-probe and analytes,and the sensitivity is mainly determined by its fluorescence contrast before and after biomolecule binding.Emission from traditional fluorogen is quenched in its aggregate state,which compels many fluorogens to operate in a fluorescence ?turn-off? mode with a narrow scope of practical applications.Aggregation-induced emission(AIE)effect provides a straightforward solution to the aggregation-caused quenching phenomenon,also it makes great contribution to the development of new fluorescent bio-probes and allows the use of highly concentrated fluorogens for bio-sensing and imaging.The simple design of sensing strategy and fluorescence ?turn-on? property of AIE-active fluorogens largely improve the sensing sensitivity and easy-operation in biological applications.Herein,the fluorogens in my thesis are based on the 9,10-distyrylanthrance(DSA)molecule,which is an AIE-active material.By introducing various groups and small molecules(quaternary ammonium salt,indometacin)towards DSA unit,we obtain new fluorogens and also study their properties in bio-sensing and bio-imaging applications.Main Contents:1.Quaternized DSA derivatives(DSAC2N,DSAC4 N,and DSAC6N)with various lengths of alkyl chains substitute are served as fluorescent probes.Three graphene oxide(GO)samples with different oxidation degrees are used as DNA structure discrimination and fluorescence quenchers.We utilize ss DNA aptamer as the recognition element together with DSA derivatives and GO to construct the label-free and ?turn-on? DNA sensor for the detection of the target DNA sequence.We investigate the supramolecular interactions of DNA with AIE probe and GO to understand the sensing mechanism and optimize the sensing performance.By tuning these supramolecular interactions,we effectively improve the sensing sensitivity for target DNA sequence with the detection limitation as low as 0.17 × 10–9 M.2.By chosen cyclooxygenase-2(COX-2)as the biological recognition unite and imaging target,we obtain a novel AIE-active and COX-2-specific bio-probe,NDSA,by combination of DSA with a COX-2-specific ligand indomethacin(IMC).NDSA displays the selective response to COX-2 according to the fluorescence test in vitro,also it can specifically light up Golgi apparatus of cancer cell lines,and the excellent biocompatibility and low cytotoxicity of NDSA make it suitable for cell imaging according to biological test including bioimaging and toxicity test.