The Study Of Functionalized Levopimaric Acid Molecularly Imprinted Electrochemical Sensor

Molecular Imprinting Technique (MIT) is widely used in chromatography, solid phase extraction, biomimetic sensing, food industry, environmental monitoring, biotechnology, drug analysis and membrane separation and so on. This article did the main research in the field of electrochemistry. Molecularly imprinted polymer has advantages of high affinity and selectivity, strong resistance to harsh environments ability, good stability, long service life and wide range of application. Electrochemical sensor has become a hot research point of scientists because of its simple operability, low cost, agility and sensitivity and wide liner range. The paper selected the ethylene glycol maleic rosinate acrylate as the cross-linking agent in building several molecularly imprinted electrochemical sensors. The main contents are as follows.The molecularly imprinted polymer membranes was created in the surface of the glassy carbon electrode by using paracetamol as template, ethylene glycol maleic rosinate acrylate as cross-linker and acrylamide as functional monomer, using free radical polymerization method. The membrane of electrochemical behavior in electrode fabrication process was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. Under the optimum conditions, the paracetamol peak currents and the analytical concentration have a good linear relationship over the range of 1.0×10 to 4.8×10-3 mol·L-1 (linear regression coefficient=0.9998) with a detection limit of 3.3×10-7 mol·L-1 (S/N=3). This electrochemical sensor displayed excellent repeatability, high sensitivity, long-term stability, and good selectivity. Paracetamol content in a sample was measured by this sensor. The recovery rate was 99.8% to 100.4%.The next part, the paper did some research in aspirin molecularly imprinted electrochemical sensor. The molecularly imprinted polymer membranes was produced in the surface of the glassy carbon electrode by using aspirin as template, ethylene glycol maleic rosinate acrylate as cross-linker and acrylamide as functional monomer, using free radical polymerization method. The membrane of electrochemical behavior in electrode fabrication process was characterized by cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy. Under the optimum conditions, the aspirin peak currents and the analytical concentration have a good linear relationship over the range of 3.6×10-6 to 1.0×10-4 mol·L-1 (linear regression coefficient 0.9998) with a detection limit of 1.2×10-6 mol·L-1. This electrochemical sensor displayed excellent repeatability, high sensitivity, long-term stability, and good selectivity. Aspirin content in a sample was measured by this sensor. The recovery rate was 99.7% to 106%.In the third part, the paper did some research in kaempferol molecularly imprinted electrochemical sensor.The molecularly imprinted polymer membranes was generated in the surface of the glassy carbon electrode by using kaempferol as template, ethylene glycol maleic rosinate acrylate as cross-linker and acrylamide as functional monomer, using free radical polymerization method. The membrane of electrochemical behavior in electrode fabrication process was characterized by cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy. Under the optimum conditions, the kaempferol peak currents and the analytical concentration have a good linear relationship over the range of 2.5×10-6 to 1.9×10-4 mol·L-1 (linear regression coefficient= 0.9998) with a detection limit of 8.0×10-7 mol·L-1. This electrochemical sensor displayed excellent repeatability, high sensitivity, long-term stability, and good selectivity. Kaempferol content in a sample was measured by this sensor. The recovery rate was 99.6% to 101.6%.In the forth part, the paper did some research in ginsenoside Rb1 molecularly imprinted electrochemical sensor. The molecularly imprinted polymer membranes was generated in the surface of the glassy carbon electrode by using ginsenoside Rb1 as template, ethylene glycol maleic rosinate acrylate as cross-linker and acrylamide as functional monomer, using free radical polymerization method. The membrane of electrochemical behavior in electrode fabrication process was characterized by cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy. Under the optimum conditions, the ginsenoside Rbl peak currents and the analytical concentration have a good linear relationship over the range of 3.1×10-5 to 3.8×10-4 mol·L-1 (linear regression coefficient= 0.9998) with a detection limit of 1.0×10-5 mol·L-1. This electrochemical sensor displayed excellent repeatability, high sensitivity, long-term stability, and good selectivity. Ginsenoside Rb1 content in a sample was measured by this sensor. The recovery rate was 96.2% to 99.5%.Then the last part, the paper studied the melamine molecularly imprinted electrochemical sensor. The molecularly imprinted polymer membranes was generated in the surface of the glassy carbon electrode by using melamine as template, ethylene glycol maleic rosinate acrylate as cross-linker and acrylamide as functional monomer, using free radical polymerization method. The membrane of electrochemical behavior in electrode fabrication process was characterized by cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy. Under the optimum conditions, the melamine peak currents and the analytical concentration have a good linear relationship over the range of 6.2×10-6 to 1.0×10-3 mol·L-1 (linear regression coefficient 0.9998) with a detection limit of 2.1×10-6 mol·L-1. This electrochemical sensor displayed excellent repeatability, high sensitivity, long-term stability, and good selectivity. Melamine content in a sample was measured by this sensor. The recovery rate was 100% to 102.6%.