Functionalized And Derived Materials Of Zeolitic Imidazolate Frameworks For Environmental Electrochemical Sensing

Today,the earth’s ecosystem is constantly being attacked by various environmental pollutants.At the same time,the biological accumulation and long-term persistence of environmental pollutants are also considered as silent killers,which seriously affect human health and social and economic development.Therefore,the development of rapid and effective means of environmental monitoring is a scientific problem that the world is being to solve.Electrochemical sensors have the advantages of fast analysis speed,high sensitivity,good selectivity,less sample required,simple operation,suitable for online analysis,wide application range,and so on.They have great application potential in the rapid and sensitive detection of environmental pollutants.In this study,two highly sensitive electrochemical sensing platforms for environmental pollutants were constructed by using the functionalized and derived materials of zeolitic imidazolate frameworks as the basic building units of the electrode interface,and using estrone and naphthol isomers as the target analysis objects,respectively.Specific work contents are as follows:1.The bimetallic AuZn-MOF was obtained by ion exchange strategy using polyhedral ZIF-8（Zn-MOF）as precursor and HAu Cl₄ as metal source.Subsequently,using Na BH₄ as reduction reagent,bimetallic AuZn-MOF composite functionalized with ultrasmall Au nanoparticles（USAuNPs/AuZn-MOF）was prepared by in situ chemical reduction.Benefit from the excellent electrochemical activity of ultrasmall Au nanoparticles,the USAuNPs/AuZn-MOF composite showed high electrochemical activity for the oxidation of estrone,which is an environmental pollutant.Based on this,A highly sensitive electrochemical sensing platform for rapid detection of estrone was constructed.The linear range of estrone was 0.05μM-5μM,the detection limit was 12.3 n M,and the sensitivity was 101.25μAμM^-1 cm^-2.It was used for the detection of real samples,and the results were satisfactory.2.The polyhedron ZIF-67（Co-MOF）was used as the precursor to obtain the nitrogen-doped porous carbon framework（N-C）by high temperature pyrolysis in an inert atmosphere.Then,the N-C adsorbed by phytic acid was activated at high temperature to obtain the N-P co-doped porous carbon framework（N,P-C）.Compared with the single-doped porous carbon frameworks,the surface defects of the N、P co-doped porous carbon framework increased and the electrochemical activity area increased.Benefit from the N,P-C framework showed more excellent activity for the electrochemical oxidation of environmental pollutants 1-naphthol and2-naphthol.Based on this,a sensing platform for simultaneous high-sensitivity electrochemical detection of 1-naphthol and 2-naphthol was constructed.The linear range of 1-naphthol and 2-naphthol was 25 n M-2μM,the detection limits were 8.0 n M and 7.2 n M,respectively.The sensitivity of 1-naphthol and 2-naphthol was 87.3μAμM^-1 cm^-2 and 84.6μAμM^-1 cm^-2.