Development Of Electrochemical Sensor Based On Molecularly Imprinted Polymer With Ethylene Glycol Maleic Rosinate Acrylate As Cross-Linker

Electrochemical sensor based on chemical or biological modification is one of the important research of electroanalytical chemistry and analytical chemistry, mainly in clinical, industrial, environmental, agricultural analysis and other fields. In recent years, experts and scholars have been committed to seeking a new sensing material of the electrode surface and the construction method of the sensitive film to preparation of the excellent performance of the electrochemical sensor. As molecularly imprinted polymer (MIP) are superior the traditional molecular recognition element, which make the sensor maintain high selectivity and sensitivity at the meantime, it also increase tolerance and prolong life. Cross-linker used to prepare MIP was almost small molecular have been reported in the literature, and there are some issues such as difficulty in elution template molecule, slow response signal, poor regeneration and reversible, high detection limit, which limit the application of MIP in sensor. This paper using ethylene glycol maleic rosinate acrylate (EGMRA) to build several electrochemical sensors based on MIP, and on this basis, we successfully constructed molecular imprinted electrochemical sensors to detect antibiotic molecular combined with excellent conductivity and catalytic performance of the multi-walled carbon nanotubes (MWNTs).The main results are list below:A molecularly imprinted polymer (MIP) was synthesized by using cinchonidine(CD) as template, modified rosin(ethylene glycol maleic rosinate acrylate) contains the skeleton of phenanthrene rings as cross-linker and methylacrylic acid as functional monomer. A MIP membrane was created on a glassy carbon electrode for determination of cinchonidine using free radical polymerization method. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) characterize the membrane of electrochemical behavior in electrode fabrication process. The experimental conditions were discussed. Under optimum conditions, it was found that the response of peak currents were linear to the concentration of cinchonidine in the range of1.3×10-5to2.26×10-3mol/L. The detection limit for cinchonidine is lμmol/L, the relative standard deviation for100μmol/L cinchonidine is1.34%and the incubation time is2min. The sensor was applied to the determination of cinchonidine in urine samples with satisfactory results.A new cross-linker agent (ethylene glycol maleic rosinate acrylate) for preparing highly sensitive, molecularly imprinted sensors was proposed for quinine determination. A MIPs film was created on a glassy carbon electrode for determination of quinine using free radical polymerization method. The modification procedure was characterized via electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The interaction between functional monomer and target molecule was observed by UV spectrometric methods. Under the optimal experimental conditions, the peak currents were proportional to the concentrations of quinine in range of8.0×10-7～2.6×10-4mol/L with the detection limit of2.0×10-8mol/L. Meanwhile the prepared sensor showed sensitive and selective binding sites for quinine. Determination of quinine in tonic water showed good recovery.A new sensitive molecular imprinted electrochemical sensor has been developed for selective detection of tetracycline by combination of multiwalled carbon nanotubes (MWNTs). MWNTs were introduced for the enhancement of electronic transmission and sensitivity. The molecularly imprinted polymer (MIP) was synthesized using tetracycline as template molecular, methylacrylic acid as functional monomer, and a homemade material (ethylene glycol maleic rosinate acrylate) as cross-linker. The electrochemical performance of the impinted film was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) in detail. Under the optimum conditions, the current response had a linear relationship with the concentration of tetracycline in two ranges of4.4×102to1.9×104μg/L and2.6x104to1.5x105μg/L, with a limit of detection8.88μ/L. The proposed sensor exhibited excellent wide range and low detection, which was better than the result from previous literature. Determination of tetracycline in tetracycline tablets showed good recovery.Based on the unique electronic properties and high adsorption capacity of carbon nanotubes as well as the specific recognition ability of molecularly imprinted polymer (MIP), a novel molecularly imprinted electrochemical sensor with high sensitivity and selectivity was constructed for determination of ultratrace oxytetracycline (OTC) in milk samples. The molecularly imprinted polymer (MIP) was synthesized using OTC as template molecular, methylacrylic acid as functional monomer, and a homemade material (ethylene glycol maleic rosinate acrylate) as cross-linker. The sensor was fabricated by directly preparing molecularly imprinted membrane of OTC on a multi-wall carbon nanotubes (MWNTs) modified glassy carbon electrode (GCE). Comparing to MIP/GCE, OTC exhibited much higher i-t current response at the MIP/MWNTs/GCE. It could be inferred that MWNTs can expand the current response signal by enhancing electron transfer on the surface of the sensor. Under optimum conditions, OTC can be determined at concentration between2×10-7and1.2×10-4mol/L with a detection limit of4.0×10-8mol/L by the chronoamperometric technique. The MIP/MWNTs sensor showed high sensitivity, selectivity, reproducibility, and good recovery in milk sample determination.