| This thesis is divided into two parts:one is electrochemical recognition of antipsychotic drugs;the other is recognition of acetylating protein based on magnetic core-shell microspheres.We provide the detailed routine for preparation of nanocompound polymers and analytes in determination process.Antipsychotic drugs are widely used in clinical treatments.In the past years, increasing attentions have been to the treatments of psychiatric disorders,stimulants determination and drugs analysis.Accordingly,antipsychotic drugs relevant to the focus above have attracted enormous interest of researchers.Many analytical methods have been developed to study them.Among these methods,owing to some advantages such as simplicity,sensitivity,rapid response,low-cost,electrochemical methods play an important role in investigating antipsychotic drugs.The object of this thesis is to study the electrochemical behaviors and mechanisms of them and establish more sensitive,simpler and accurate quantitative methods by means of chemically modified electrodes.The new methods are expected to apply in the practical stimulants determination and drugs analysis.In addition,we also presented a novel and simple approach to create hydrophilic and uniform magnetic core-shell imprinting microspheres(MCSIMs) for the template recognition.MCSIMs combined the biocompatible silica shells as the recognition interface and immobilization matrix with magnetic microspheres as separation tool.Because of a high magnetic responsivity to magnetic fields and surface pores formed onto the silica shells,the prepared MCSIMs could be used to rebind analytes with the help of an applied magnetic field.In chapter 1,we pointed out the importance of this thesis,described briefly the classification of antipsychotic drugs,proteins recognition,chemically modified electrode and molecularly imprinting technique.We suggested studying them by using chemically modified electrodes.Then,the electropolymer modified electrodes,Pt nanoparticles and carbon nanotubes(CNTs) were discussed in detail.Thirdly, magnetic core-shell imprinting microspheres were introduced to recognize analytes. Finally,the research scheme of this thesis was proposed.In chapter 2,the electrochemical behaviors and mechanisms of phenylephrine at poly-aminobenzene sulfonic acid(ABSA) modified glassy carbon electrode were studied.It was found that phenylephrine generated an irreversible anodic peak at about +0.89V(vs.SCE) in 0.05M HAc-NaAc(pH=5.0) buffer solution at the modified electrode.Sensitive and quantitative measurement for phenylephrine based on the anodic peaks was established under the optimum conditions.The anodic peak current was linear to phenylephrine concentrations from 1×10-7M to 1.5×10-5M,the detection limits obtained was 1×10-8M.The modified electrode exhibited some excellent characteristics including easy regeneration,high stability,good reproducibility and selectivity.The method proposed was successfully applied to the determination of phenylephrine in drug injections and proved to be reliable compared with ultraviolet spectrophotometry(UV).The modified electrode was characterized by electrochemical methods.In chapter 3,a poly-ABSA/SWNTs composite-modified electrode was fabricated by electropolymerizing ABSA on the surface of glassy carbon electrode modified with single-wall carbon nanotubes(SWNTs).SWNTs provide a 3D porous and conductive network for the polymer immobilization.The nanocomposite film was characterized by scanning electron microscope(SEM) and electrochemical impedance spectroscopy (EIS).The results indicated that this composite-modified electrode had strong electrocatalytic activity toward the oxidation of trifluoperazine(TFP).TFP could effectively accumulate on the modified electrode and generate a sensitive anodic peak at 0.72V(versus SCE) in pH 6.1 phosphate buffer solution.Under the selected conditions,the anodic peak current of TFP was linear with its concentration within the range from 1.0×10-7 to 1.0×10-5M and 1.0×10-5 to 1.0×10-4M,and the detection limit was 1.0×10-9M(S/N=3).This method was successfully applied to the detection of trifluoperazine in drug samples and the recovery was satisfactory.In comparison with the SWNTs/GCE or poly-ABSA/GCE prepared in the similar way,this composite-modified electrode exhibited better catalytic activity.In chapter 4,clomipramine,an important tricylic antidepressant drug with low redox activity,was effectively electrocatalyzed on poly-ABSA/Pt nano-clusters modified glassy carbon electrode(i.e.poly-ABSA/Pt/GCE) and generated a sensitive anodic peak at about 0.80V(vs.SCE) in pH 8.1 PBS.ABSA was electropolymerized on the surface of Pt matrix pre-electrodeposited on GCE.Pt microparticles provide a 3D and conductive structure for the polymer immobilization.The resulting sensor exhibited a considerable enhancement in voltammetric response characteristics: extending the linear range and lowering the detection limit.The anodic peak current was linear to clomipramine concentration over two concentration intervals,viz, 1.0×10-7～4.0×10-6M and 4.0×10-6～4.0×10-5M,with the detection limit of 1.0×10-9 M.This method was successfully applied to the detection of clomipramine in drug tablets and proved to be reliable compared with UV.The poly-ABSA/Pt composite film surface features,A.C.impedance and other electrochemical characteristics were also studied in detail.In chapter 5,novel superparamagnetic core-shell imprinting microspheres (MCSIMs) were synthesized using magnetite microspheres with 350 nm diameter and 70nm thicknesses silica gel to form core-shell Fe3O4/SiO2 composite for template phenylephrine(Phen) recognition and high efficient separation.Compared to the previous imprinting recognition,the main advantage of this strategy lies in two aspects:one is the high stability and monodispersity of MCSIMs structure,the other is the use of superparamagnetic Fe3O4/SiO2 microspheres as immobilization matrix and separation tool,thus greatly simplifying time-consuming washing steps.The affinity and selectivity of the MCSIMs were monitored by QCM and electrochemistry measurements.Imprinting microshpheres have a remarkable affinity to Phen over that of structurally related molecules,including DA,EP,Phe and Tyr.The relative binding selectivity for different analytes estimated from amperometric signals was Phen:DA:EP=40:5:1.The MCSIMs sensor showed a high sensitivity(400μA mM-1), short response time(reaching 98%within 10s),and broad linear response range from 1μM to 0.1mM and low detection limit(0.1μM).Additionally,the results of control experiments showed that only negligible signal was obtained for non-imprinting microspheres.This could be reasonably attributed to the unique surface pores,charges and especially the nature of the functional groups inside MCSIMs cavities.In chapter 6,recognition of acetylating protein based on magnetic core-shell microspheres was explored.We provide the detailed routine for preparation of microcompounds and determination of analytes.Firstly,carbonyl group agent was introduced on the surface of magnetic silica shell.Secondly,functional magnetic silica microspheres was hatched with acetylating protein and separated with the help of magnetic field.Finally,the compounds of magnetic microspheres and acetylating proteins are detemined by MALDI-TOF-MS.In chapter 7,we summarized and gave objective comments on the results obtained.Meanwhile,the problems and shortcomings of this thesis were pointed out. Finally,we proposed the objects and schemes of further research.
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