Preparation Of Molecularly Imprinted Polymers And Application In Pharmaceutical Detection

The safe use of drugs has important significance to assure the human health and environment.However,with increase of variety an quantity of the drugs,problems which caused by the safe use of drugs have attracted more an more attentions.Developing detection method to drugs is very important to improve the safe use of drugs and the living quality of human beings.In recent years ,the development of sensitive robust method for real-time,trace analysis has attracted considerable research efforts. Theophylline(THO), also known as dimethylxanthine, is a methylxanthine drug therapy for respiratory diseases, The main actions of theophylline involve: increasing heart rate, diuresis, dilating coronary artery, relaxing bronchial smooth muscle, stimulatory central nervous system,while, using too much may cause numerous side-effects.Herein,theophylline was used as analyte,molecularly imprinted polymers nanoscale were synthesized,and combining with Surface-enhanced Raman Scattering technique,molecularly imprinted polymer sensors for theophylline recongnition were also prepared .(1) Nanoscale molecularly imprinted polymers have many advantages,such as high density of effective recognition sits and fast rebinding kinetics.Here,a layer-by-layer molecular imprinting strategy was used to synthesize the gelatin-building molecular recognition sites at the surface of silica particles. The imprinting complex was prepared by intermolecular interaction between carboxyl group of gelatin and theophylline,then the imprinting complex was assembled onto the amine-capping silica particles by the covalent interaction between amino group and aldehyde group providing by glutaraldehyde. The shell thickness can be tuned at the nanometer scale by controlling the number of layers.The results showed that imprinted microspheres had recognition ability to theophylline,and had selectivity to theophylline between theophylline and its analogues,caffine.The new molecular imprinting strategy bulided by protein provide a more approaching mimic of antibody,can be used in the field of nanosensors and drug release.(2) Based on the enhancement of Raman signals to the ananlytes absorbed on nanostructured noble metal surface, molecularly imprinted polymers embedded with in stiu grown Ag nanoparticles were prepared.Firstly,the Ag+ ions were introduced into the molecularly imprinted precursor mixture, The imprinting complex was formation by intermolecular interaction between theophylline and functionl monomer(MAA),and by coordination interaction between theophylline and Ag+ ions. Under nitrogen atomosphere,the mixture system was irradiated by ultraviolet light,the simultaneous polymerization and reduction process directly disperse the resulting silver nanoparticles in the molecularly imprinted polymer matrix.Then the resulting polymers were reduced with sodium borohydride,to achieve Ag nanoparticles further induce growth,so as to introduce active surfaces for Surface-enhanced Raman Scattering.It has been demonstrated that this molecularly imprinted polymer can realize the signals output and signal response after the rebind of templates,and also has high selectivity,high affinity and fast rebinding kinetics.This new strategy of prepared sensors may found potential application in biological immunoassay, biomimics, chemical and biological sensors, chemical catalysis, environment detection, drug release and other relevant fields .