Study Of Molecularly Imprinted Electrochemical Sensor For Antitumor Drugs Based On Conductive Polymeric Membrane

With the continuous development of social economy,the living standard of human being is increasing day by day.At the same time,the corresponding highlights the many social problems,such as the aging of the population,the destruction of the ecological environment,food safety problems and modern unhealthy lifestyles,is resulting in the increasing number of people suffering from cancer.In recent years,the incidence of cancer in China is close to the world level,but the mortality rate is higher than the world level.Even more serious is that this momentum has not been effectively curbed.At present,anti tumor drugs can be used for the clinical treatment of many cancers,but its presence in the body weight directly affect human health,so it is necessary to establish a rapid,sensitive and accurate method for identification and detection of the drug,and it has important practical value in the diagnosis of diseases related to the rapid and effective.In this paper,doxorubicin hydrochloride,vincristine and levofloxacin as the main research object,selective recognition of object of study by molecular imprinting technique,using electrochemical technology as the main means of detection,molecular imprinting technique and electrochemical sensors effectively combined.The nanocomposite films with good conductivity and biocompatibility were prepared on the surface of a substrate electrode through self-assembly,electrochemical polymerization,construct a series of molecularly imprinted sensor for anti cancer drugs based on conductive polymer,and the recognition mechanism is discussed.The performance of nanocomposite film with large specific surface area and strong electrical conductivity can significantly improve the current response of the sensor,the effective recognition ability to target molecule and the sensitivity of detection.After optimizing the experimental conditions,the sensor was applied to life and its practical value was investigated.It is expected to construct a rapid,sensitive and accurate method for the identification and detection of the drug.The main contents are as follows:1.An electrochemical sensor was developed for the determination of doxorubicin hydrochloride(DOX)using the molecularly imprinted technique.A molecular imprinted polymer(MIP)on the surface of a gold electrode was prepared by electropolymerization of 3,4-ethylenedioxythiophene(EDOT)in the presence of DOX in the phosphate buffer solution.Under the optimum conditions,the properties of the electrochemical sensor modified with DOX-imprinted membrane were characterized by cyclic voltammetry,differential pulse voltammetry and electrochemical impedance spectroscopy.A linear relationship between oxidation peak current and DOX concentration was obtained over the range of 4.0 × 10-7—1.0 × 10-6 mol/L with a correlation coefficient of 0.9967 and a detection limit(S/N = 3)of 6.5 × 10-8 mol/L.After regeneration by washing with electrochemical method,the sensor showed excellent reproducibility and good stability.The MIP electrode exhibited very weak response to vinblastine,actinomycin D and fluorouracile,proving a good selectivity.The imprinted sensor was applied to the determination of doxorubicin hydrochloride in human blood serum samples with the relative standard deviation(RSD)below 4 % and recovery ranging from 96.0 % to 106.7 %.2.An innovative molecularly imprinted electrochemical sensor was fabricated based on reduced graphene oxide(RGO)and gold nanocomposite(Au)for rapid detection of vincristine(VCR).The RGO-Au composite membrane was obtained via directly one-step electrodeposition technique of graphene oxide(GO)and chloroauric acid(HAuCl4)on the surface of a glassy carbon electrode(GCE)by means of cyclic voltammetry(CV)in the potential range between-1.5 and 0.6 V in phosphate buffer solution(PBS)pH 9.18,which is capable of effectively utilizing their superior electrical conductivity,larger specific surface area due to its synergistic effect between RGO and Au.The molecularly imprinted polymers(MIPs)were synthesized on the RGO-Au modified glassy carbon electrode surface with VCR as the template molecular,methyl acrylic acid(MAA)as the functional monomer,and ethylene glycol maleic rosinate acrylate(EGMRA)as a cross-linker.The performance of the sensor was investigated by cyclic voltammetry(CV),differential pulse voltammetry(DPV)and electrochemical impedance spectroscopy(EIS)in detail.Under the optimum conditions,the fabricated sensor exhibited a linear relationship between oxidation peak current and VCR concentration was obtained over the range of 5.0 × 10-8-5.0 × 10-6 mol/L with a correlation coefficient of 0.9952 and a detection limit(S/N = 3)of 2.6 × 10-8 mol/L.The results indicated that the imprinted polymer films exhibited an excellent selectivity for VCR.The imprinted sensor was successfully used to determine VCR in real samples with recoveries of 90 %-120 % by using the standard addition method.3.A novel imprinted electrochemical sensor was developed based on prussian blue(PB)modified glassy carbon electrode with levofloxacin(LVFX)as the template molecule and pyrrole as the functional monomer.The electrochemical performances of the molecularly imprinted sensor were characterized with cyclic voltammetry(CV)and electrochemical impedance spectroscopy(EIS).The imprinted sensor performance was optimized by using differential pulse voltammetry(DPV)method.The results showed that the response current of the imprinted sensor revealed a linear relationship with the LVFX concentrations range of 6.0 × 10-8-1.0 × 10-5 mol/L with the detection limit of 1.7 × 10-8 mol/L(S/N = 3).The molecularly imprinted electrochemical sensor was successfully used to detect LVFX in real samples with the recoveries of 96 %-105 %.