Detection Of Organic Substances In Aquatic Products By Metal-organic Framework Modified Electrode

Metal organic framework materials（MOFs）are a kind of porous chemical materials,which have the advantages of simple preparation method,high porosity and crystallinity,large surface area,and regular internal arrangement.The application of MOFs and their composites in electrochemical sensors has become a hot topic in electrochemical sensor research.In this study,cobalt（II）-terephthalic acid metal organic framework materials（Co（BDC））,aluminum（III）-trimellitic acid metal organic framework materials（Al（BTC））and zinc（II）-terephthalic acid metal organic framework materials（Co（BDC））were synthesized.The prepared materials were characterized by SEM,FT-IR,BET and TG.Using the film forming property of sodium polyacrylate（PAAS）,the synthesized materials were fixed on the surface of the electrode to construct fast and sensitive electrochemical sensors for detecting ciprofloxacin（CIP）,malachite green（MG）and trimethylamine（TMA）.The main contents are as follows:1.Co（BDC）was synthesized by hydrothermal method using cobalt nitrate hexahydrate（Co（NO₃）₂·6H₂O）and terephthalic acid（H₂BDC）as raw materials and N,N-dimethylformamide（DMF）as solvent.Co（BDC）was mixed with PAAS and applied dropwise to the surface of the electrode to prepare Co（BDC）-PAAS/GCE.The modified electrode was electrochemically characterized by cyclic voltammetry（CV）,which showed that in alkaline conditions,Co（BDC）-PAAS/GCE had a good electrocatalytic effect on CIP.The response of Co（BDC）-PAAS/GCE to CIP was investigated by differential pulse method（DPV）.The results showed that the peak current difference（ΔI）increased with the CIP concentrationin the range of 3.02×10^-9mol/L¹.51×10^-88 mol/L with a calibration equation of I（μA）=103.44X+5.699（mol/L,R²=0.9940）.And in the range of 1.51×10^-88 mol/L¹.51×10^-77 mol/L with a calibration equation of I（μA）=11.098X+7.089（mol/L,R²=0.9937）.The detection limit was 1.03×10^-9 mol/L.Which could be applied to the detection of CIP in the actual aquatic products successfully2.Al（BTC）was synthesized by hydrothermal method using aluminum nitrate nonahydrate（Al（NO3）3·9H2O）and 1,3,5-benzenetricarboxylic acid（H3BTC）as raw materials and DMF as solvent.Al（BTC）was mixed with PAAS and applied dropwise to the surface of the electrode to prepare Al（BTC）-PAAS/GCE.The electrochemical behavior was investigated by CV method,which showed that Al（BTC）-PAAS/GCE had good electrocatalytic effect on MG in alkaline conditions.The response performance of Al（BTC）-PAAS/GCE to MG was investigated by DPV.The results showed that theΔI with the MG concentrations in the range of 2.74×10^-99 mol/L¹.37×10^-88 mol/L with a calibration equation of I（μA）=99.699X+6.9822（mol/L,R²=0.9976）;And in the range of 1.37×10^-88 mol/L⁶.85×10^-88 mol/L with a calibration equation of I（μA）=19.007X+8.022（mol/L,R²=0.9915）.The detection limit was 0.91×10^-9 mol/L.Which could be applied to the detection of MG in the actual aquatic products successfully.3.Zn（BDC）was synthesized by hydrothermal method using zinc nitrate hexahydrate（Zn（NO3）2·6H2O）and H2BDC as raw materials and DMF as solvent.Zn（BDC）was mixed with PAAS and applied dropwise to the surface of the electrode to prepare Zn（BDC）-PAAS/GCE.The electrochemical behavior was characterized by CV method,which showed that had good electrocatalytic effect on TMA.The response of Zn（BDC）-PAAS/GCE to TMA was investigated by DPV method.The results showed that theΔI increased with the TMA concentrations in the range of1.05×10^-8mol/L⁵.23×10^-8mol/L with a calibration equation of I（μA）=49.713X+5.163（mol/L,R²=0.9960）;And in the range of 5.23×10^-88 mol/L⁵.23×10^-77 mol/L with a calibration equation of I（μA）=11X+7.0075（mol/L,R²=0.9992）.The detection limit was 3.28×10^-9 mol/L.Which could be applied to the detection of TMA in the actual aquatic products successfully.