| In recent years,terrorist events had been frequently happened,the related methods and techniques of counter-terrorism had been a widespread concern around the world.As a new type of explosives,the peroxide explosives are widely used in terrorist attacks by terrorists because of their characteristics,such as easy access from raw materials,simple synthesis and high explosive power.However,there is neither UV absorption nor fluorescence emission for the peroxide explosives,and its chemical structure is lack of nitro group and aromatic hydrocarbon,therefore,the analysis and detection is still facing a significant challenge.At present,the molecular fluorescence probe had been developed to be one of important detection methods,due to their advantages,such as high sensitivity,good selectivity,simple operation,easy to carry and so on.The peroxide explosives contain unstable peroxide group(-O-O-),which is easy to produce hydrogen peroxide(H2O2),and H2O2 is also the necessary material for the synthesis of peroxide explosives.As a result,the effective monitoring and early warning of the peroxide explosives is expected to be achieved by the analysis and detection of the signal molecule H2O2 of the peroxide explosives.Therefore,in this study,benzils were used to be the high-selectivity identification groups of H2O2 and boron-dipyrromethene(BODIPY)as fluorophore with some advantages(good stability,light extinction coefficient and so on),two novel fluorescent probes: 4-(4-nitro-benzyl)-boron-dipyrromethene(PBD-3)and 3-(4-nitro-benzyl)-boron-dipyrromethene(MBD-3)for detecting H2O2 were synthesized.Moreover,their chemical structures,spectrum properties,and detection performance were characterized,investigated,and discussed,respectively.Specific work were as followed:(1)With 3-iodobenzoyl chloride,4-iodobenzoyl chloride,2,4-dimethyl pyrrole and 4-nitrobenzene acetylene as the starting material,the two novel hydrogen peroxide fluorescent probes PBD-3 and MBD-3 were designed and synthesized succesfully by Friedel-crafts acylation reaction,Sonogashira coupling reaction,PdI2-DMSO oxidation and other chemical reactions.The chemical structure of new probe and related intermediates were characterized by 1H NMR,13 C NMR and high resolution mass spectrometry.(2)The fluorescence properties of novel fluorescent probes and their hydrogen peroxide derivatives were investigated.The two novel fluorescent probes used nitrobenzene benzil as the recognition group and BODIPY as fluorophore.The fluorescence of the probe itself was very weak.After the probe fully reacted with hydrogen peroxide,the fluorescence intensity was increased,and the strong green fluorescence was visible by the naked eye based on d-PET mechanism.The probe and its hydrogen peroxide derivative product had excellent light stability.Continuous illumination for 3 hours,the fluorescent intensity of probe PBD-3 and MBD-3 remained unchanged,the fluorescence intensity of derivatives to probe reacted with H2O2 were still maintained at 92% and 86%,respectively.(3)The detection performance of the new probe was discussed.The probe PBD-3 and MBD-3 have high selectivity to H2O2,which was not easy to be disturbed by the degradation products of nitro explosive,nitro explosive and the active small molecule.The probe PBD-3 and MBD-3 also have high sensitivity and the detection limits are 0.9 ?mol/L and 1.4 ?mol/L,respectively.(4)The response of the new probes of PBD-3 and MBD-3 with H2O2 vapor were studied.The two new probes can respond well to H2O2 vapor,and the response was quick and sensitive. |
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