Farbrication Of Nanoscale MOFs Materials And Applied Research For Sensing

With the development of industry,the discharge of industrial wastewater has increased,resulting in serious excess of Fe3+ and nitroaromatic molecules in aquatic ecosystems,and has gradually become one of the main pollutants.As the fourth important transition metal ion in biological systems,Fe3+plays a vital role in various biological processes.Nitroaromatics are highly explosive and toxic,which not only cause serious pollution of the ecological environment,but also threaten human health.Therefore,the selective detection of Fe3+and nitroaromatics is of great significance for human health and environmental protection.Compared with the traditional detection method,fluorescence detection has the advantages of high sensitivity,high selectivity,low cost,and simple preparation of samples.In recent years,fluorescent sensors based on luminescent MOFs,with their diverse structure,rich functional sites,large specific surface area and excellent stability,have become potential chemical sensors,showing an attractive prospect in the field of fluorescence detection.At present,the application research of MOFs is mainly focused on the farbrication and performance study of bulk-sized MOFs materials.However,in the water environment and biological field,the bulk-sized MOFs are greatly limited in the field of fluorescence sensing due to their small specific surface area,poor dispersion and poor contact with specific target analytes.At the same time,due to the easy powdering characteristics of MOFs,it is difficult to recycle and made into device.In order to solve this problem,we have studied the fluorescence detection performance and feasilibity of forming device of the synthetic materials by fabricating nanoscale luminescent MOFs.The research's process and conclusions are as follows:(1)A rare nanoscale luminescent Titanium-based MOF-ZSTU-1 nanorod was synthesized by solvothermal method using H3TCA and Ti4+.The microscopic morphology of the material is uniform nanorod.The fluorescence detection performance experiment was carried out,and it was found that ZSTU-1 nanorod achieved nanomolar detection for Fe3+ with a detection limit of only 63.8 nM and a quenching coefficient of 2.69×106 M-1.At the same time,this is the first time that Titanium-based MOF is used to detect nitroaromatics.Both in liquid and gas phases,ZSTU-1 nanorod also shows sensitive sensing properties for detecting nitroaromatics.The detection limit of PA is 12.3 ?M and the quenching coefficient is 3.59×104 M-1.And we have successfully prepared a simple fluorescent test paper for rapid and intuitive detection of trace amounts of Fe3+and nitroaromatics in this field with portability and better practical applications.(2)Nanoscale luminescent Titanium-based MOF named ZSTU-3 which was the same topological structure with ZSTU-1 nanorod was synthesized by organic ligand H3BTCA and metal ion Ti4+.ZSTU-3 is also a multi-response fluorescent sensor for Fe3+ and nitroaromatic.The detection limit of Fe3+ is only 70.7 nM and the quenching coefficient is 2.36×105 M-1.The detection limit of PA is 15.9?M and the quenching coefficient is 4.25×104 M-1.Then a fluorescent test paper with the advantages of portability and low cost was prepared for qualitative detection of Fe3+ and nitroaromatics.(3)A luminescent MOF of Zr-TCA nanoflower material composed of nanosheets was synthesized by metal ions Zr4+ and organic ligand H3TCA.According to the fluorescence detection experiment,the Zr-TCA nanoflower material showed better sensing performance for detecting nitroaromatics.The detection limit of PA was only 0.36?M and the quenching coefficient reached up to 2.60×105 M-1.Then Zr-TCA nanoflower@CAF was prepared by combining Zr-TCA nanoflower with cellulose acetate film.Zr-TCA nanoflower@CAF not only exhibits sensitive sensing properties for liquid phase nitroaromatics,but also exhibits excellent sensing properties for gas phase nitrobenzene with a quenching efficiency of 95%.In the gas phase of nitrobenzene detection,the fluorescence intensity of Zr-TCA nanoflower@CAF is remained above 90%after five cycles,which has excellent recyclability.And it also provides a new pathway for the fabrication of MOFs device.