Study On Preparation And Properties Of Several Kinds Of Phenolic Hydroxyl Drugs Based On Molecularly Imprinted Electrochemical Sensors

Molecular Imprinting Technology(MIT) is artificial designed and synthesized a novel technique for target molecules with predetermined selectivity. With the characteristics of predetermination, recognition and practicability, molecularly imprinted polymers are used in many fields, such as film separation, solid phrase extraction, chemica bionics sensor and so on. Molecularly imprinted membrane has both advantages of the membrane and molecular imprinted polymer, so that molecularly imprinted membrane is becoming the hot topic of research. But the traditional preparation of molecularly imprinted membrane methods are slow signal response, incomplete template removal, bad reversibility, which limited application of molecularly imprinted membrane in sensors. In comparison with the traditional procedures, the molecularly imprinted membranes prepared by electropolymerization have superior properties with respect to adherence to the transducer surface, simplicity and speed of preparation, easy control of the film thickness and high reproducibility.This paper gives a summary of the development of the molecularly imprinted technology and the molecularly imprinted electrochemical sensors. Molecularly imprinted electrochemical sensors for salicylic acid, p-hydroxy benzoic, ascorbic acid were by electrochemical polymerization on the surface of graphite electrode using o-phenylenediamine(o-PD) and pyrrole composite monomor. The polymer films and characeristics of sensor were investigated. The main work is as follows:(1) The molecularly imprinted electrochemical sensor was prepared by electropolymerization with salicylic acid as the template, and o-PD and pyrrole as functional monomer on a graphite electrode. The morphology and electrochemical property of the film were characterized by SEM and square wave voltammetry(SWV). The fabrication conditions that affect the performance of the imprinted sensor, such as elution time, scan cycles and p H, have been discussed. Under the optimized conditions, the characteristics of the sensor were studied by SWV, the results showed that the peak current was linear to the negative logarithm of SA concentration in the range from 1.0×10-10- 1.0×10-3 mol/L, with a detection limit(S/N=3) of 1.101×10-11 mol/L. The life of sesor reached a month. The sensor was applied to determinate samples with relative error as 3.43% and recovery 95.58%-96.13%.(2) A molecularly imprinted electrochemical sensor was prepared by electropolymerization with by electropolymerization with p-hydroxy benzoic(PHB) as the template, and o-PD and pyrrole as functional monomer on a graphite electrode. The morphology and electrochemical property of the film were characterized by SEM and SWV with ferricyanide as an electrochemical probe. The preparation conditions that impact the performance of the imprinted sensor, such as scan cycles, p H and the ratio of template monomer, have been discussed. Under the optimized conditions, the performances of the sensor were investigated and the results showed that the peak current was linear to the negative logarithm of PHB concentration in the range from 1×10-8—5×10-4mol/L, with a detection limit(S/N=3) of 2.73×10-9mol/L and with relative error as 3.43%. The sensor has strong anti interference ability and service life reached 35 days.(3)A novel molecularly imprinted electrochemical sensor was prepared by electropolymerization with by electropolymerization with ascorbic acid(AA) as the template, and o-PD and pyrrole as functional monomer on a graphite electrode. The morphology and electrochemical property of the film were characterized by SEM and SWV with ferricyanide as an electrochemical probe. The preparation conditions that impact the performance of the imprinted sensor, such as elution time, scan cycles, p H and the ratio of template monomer, have been discussed. Under the optimized conditions, the performances of the sensor were investigated and the results showed that the peak current was linear to the negative logarithm of AA concentration in the range from 1×10-6—1×10-3 mol/L, with a detection limit(S/N=3) of 2.63×10-7mol/L. The life of sesor reached 20 days. The sensor was applied to determinate samples with relative error as 5.24% and recovery 95.71%-105.98%.