Development Of New Photosensitive Materials And Their Application In Nitroaromatic Explosive Sensing

Under the tremendous pressure of global anti-terrorism and increasing demand for environmental protection,the detection of explosives is becoming more and more important.Nitroaromatic explosives are usually used in terrorist explosion attacks and have biological toxicity.Therefore,the detection of nitroaromatic explosions,especially rapid and sensitive method for detecting nitroaromatic explosives,which has become a research hotspot.Organic-inorganic hybrid materials have unique properties in light,electricity,catalysis,adsorption and magnetism,thus it have potential application value in sensor materials.Compared with conventional methods,fluorescence spectroscopy and surface enhanced Raman scattering spectroscopy（SERS）have attracted more attention for their high sensitivity,simplicity,low cost,non-destructive detection and real-time detection.Based on the above,organic-inorganic hybrid materials are selected as fluorescent sensors and SERS sensors for rapid and sensitive detection of nitroaromatic explosives.The main conclusions have been obtained as follows:（1）Compounds with conjugatedπelectron systems generally have strong fluorescence effect,which can be used identify the tested substances with naked eyes.Fluorescent materials with aggregation-induced emission enhancement（AIEE）effect can improve the sensitivity.Cd（II）-H₃BTT metal-organic complexes were synthesized by 4,5-bis（1H-tetrazole-5-yl）-2H-1,2,3-triazole（H₃BTT）and Cd（NO₃）₂.4H₂O and showed obvious AIEE characteristics in anti solvent ethanol.Moreover,it displayed highly sensitivity and selectivity for picric acid（PA）by fluorescence quenching.（2）Metal orginc framworks（MOFs）have high specific surface area and exposed sites,and have certain adsorption effect on small molecules.Precious metal silver can provide the electromagnetic field needed for SERS enhancement.Therefore,four MOFs@Ag composites were prepared by photoreduction method as SERS substrates.The substrate materials with good SERS properties were ZIF-8 and CuBTC.（3）4-Mercaptophenol（4-ATP）and trinitrotoluene（TNT）can produce aπ-πconjugate interaction,which leads to chemical enhancement of SERS.So 4-ATP can be used as a SERS probe for TNT.4-ATP was modified on the surface of ZIF-8@Ag composite by self-assembly technology.The 4-ATP functionalized ZIF-8@Ag composite has high sensitivity and selectivity to detection TNT.（4）Large area array structure can provide a uniform SERS signal.CuBTC arrays were grown by layer-by-layer self-assembly method with simple preparation and controllable thickness.The optimum growth conditions of CuBTC arrays were obtained.Silicon column arrays can be used as the substrate for layer-by-layer self-assembly method,but PS sphere arrays are not suitable.