The Small Molecular Fluorescent Probe Based On NBD Fluorephore:Design,Synthesis And Studies On The Application Of Fluorescence Detection

Nitro-benz-2-oxa-1,3-diazole?NBD?is a compound that have a nitro group at the seven position of benzoxadiazole.This compound is a kind of important fluorophore among fluorescent groups,and the derivatives of NBD that containing an amino group at the forth position have a lots of advantages in fluorescent properties,such as small molecular weight,good solubility in water,high molar absorption coefficient,high quantity of fluorescence,sensitive in environment,good biological compatibility and fluorescence wavelengths in the visible light region,etc.In context,this thesis is to design and develope multi-functional small molecule fluorescent probe based on NBD to detect metal ions and biological small molecules.1)Fourteen NBD fluorescent probes?2a-2n?were designed and synthesized to detect Pd²⁺ based on the chemical properties of Pd²⁺.?1?Six fluorescent probes?2a,2b,2c,2h,2i,2l?were obtained,which can detect Pd²⁺ through the obvious fluorescence quenching;?2?The probes exhibted high selectivity for Pd²⁺,and can not be influenced by the other ions;?3?The probes exhibited high sensitivity and low detection limit?0.04-0.60 nM?for Pd²⁺;?4?The probes can form the mole ratio of 1:1 complexed with Pd²⁺,and the sequence of coordination constant is 2a> 2l > 2i > 2h > 2c > 2b.For the application of 2a,the research showed that: it can be used for cell imaging;it can prepare the test paper,which can be used for detected 3-10 ppm Pd²⁺ through color changing;it can be used for the actual water samples detecting Pd²⁺.Conclusion: Six fluorescent probes with high selectivity and high sensitivity were obtained for Pd²⁺,and the probes can be used for the actual water samples detecting Pd²⁺.2)According to the reducibility of CO,seven NBD fluorescent probes?3a-3g?were designed and synthesized to detect CO.The results showed that:?1?The probes exhibited high selectivity and high sensitivity for Pd0,and accord with the condition as the CO fluorescent probes;?2?The probes exhibited high selectivity for CO,and can not be influenced by the other ions;?3?The probes can detect CO with colorimetric and fluorescence,and can detect CO by naked eyes;?4?The probes exhibited high sensitivity and low detection limit?26.3-227.4 nM?to detecting CO;For the application of 3c,the research showed that: 1)It can be utilized to sensing intracellular CO level in living cells;2)It can be used as an efficient and convenient visual indicator for CO gas in air.Conclusion: Seven CO fluorescent probes were obtained based on NBD fluorophore for the frist time;the probes exhibited high selectivity and high sensitivity for detecting CO;the peobes can be utilized to cell imaging and detected CO gas in air by naked eyes.3)Four NBD fluorescent probes?4a-4d?for H₂S were designed and synthesized based on nucleophile.?1?Two responsive probes were obtained by filtering the four NBD fluorescent probes;?2?The probes can high selectively detect H₂S;?3?The probes can detect H₂S with colorimetric and fluorescence,and can detect H₂S by naked eyes.Comparing the compound structure,the research showed that: a)The piperazine ring is the essential group for 4b and 4d to detect H₂S;b)The NBD-PZ can detect H₂S with high selectivity;c)The piperazine ring is the important structure for NBD fluorophore to develop fluorescent probe for detecting biothiol.Conclusion: two fluorescent probes were obtained with high selectivity for H₂S,and the piperazine ring is the important structure for developing thiol fluorescent probe besed on NBD fluorophore.