Preparation Of High-performance Imprinted Materials And Its Application In The Detection Of Amphetamines

Drug substances(such as methamphetamine and ketamine)are a class of psychoactive substances,and have many medical applications in different countries and regions.But drug abuse can have a devastating effect on the human nervous system and brain,and may lead to addiction.Moreover,drug abuse will bring huge hidden dangers to the harmonious development of society,economic stability and the safety of people’s lives and property.Therefore,it is necessary to carry out rapid and accurate detection of drugs.The thesis mainly uses carbon nanomaterials,magnetic nanoparticles and metal organic framework materials(MOFs)as carrier materials,and uses molecular imprinting methods to prepare surface imprinted polymers.Investigate the performance of composite materials,and different electrochemical sensors were prepared by combining composite materials with electrochemical detection,which are used in the detection of drug molecules in actual samples.The research content of the thesis is as follows:1.The surface molecularly imprinted polymer material of magnetic graphene(r GO@Fe3O4)was prepared by surface molecular imprinting synthesis method and the specific adsorption of methamphetamine(MA)was successfully achieved.The materials were characterized by ultraviolet spectroscopy,TEM,thermodynamics,kinetics and other methods.The results showed that when the molar ratio of template molecule(MA): functional monomer(MAA): cross-linking agent(EGDMA)is 1:2:20,methamphetamine molecularly imprinted polymer materials(MA-MIPs)to MA has good affinity,selective adsorption and regeneration performance.The imprinted polymer has an equilibrium adsorption capacity of 101 mg g-1 in 5 m L of MA solution containing 0.2 mg ml-1,and the imprinting factor is IF = 1.67.2.Ketamine molecularly imprinted polymer film(KT-r GO@MOFs-MIM)based on graphene and metal-organic framework composites(r GO@MOFs)was prepared by UV polymerization on the surface of screen-printed electrodes.The molecularly imprinted membrane is used as a sensitive element to construct a molecularly imprinted electrochemical sensor for sensitive detection of ketamine in biological samples.The performance of the composite material and sensor were studied by scanning electron microscope and electrochemical analysis.The results showed that the concentration of ketamine and its current response showed a good linear relationship in the range of 1.0 × 10-10 mol L-1 to 4.0 × 10-5 mol L-1,and the detection limit was 4.0 × 10-11 mol L-1.The established method has been successfully applied to the determination of ketamine in blood and urine.3.Modified electrodes were prepared based on carbon nanohorn-loaded platinum nanoparticle composites(CNHs-CHI@Pt NPs)for simultaneous detection of morphine and MDMA(ecstasy).The performance of the material and sensor were studied by scanning electron microscopy and electrochemical detection.The results showed that the prepared materials have good electrocatalytic activity on morphine and MDMA.Under optimized conditions,the peak current of morphine and MDMA has a good linear relationship with its concentration in the range of 0.05 × 10-6 to 25.4 × 10-6 mol L-1.The detection limits were 0.018 and 0.008 mol L-1,respectively.The sensor showed good sensitivity and accuracy.It was used to detect low concentrations of morphine and MDMA simultaneously or separately,and the results were satisfactory.