| As a semiconductor material,ZnO has the advantages of wide band gap（3.37 e V）,high exciton binding energy（60 Me V）,good biocompatibility,non-toxic,low cost,higher potential point（IEP）and is suitable for adsorption of proteins with low IEP,which makes ZnO can be used in many fields such as photocatalysis,electrochemical biosensor and so on.However,it also has disadvantages such as poor conductivity and poor cycling ability as electrode modifier.The morphology and structure of ZnO materials can be improved by compounding with metals and their oxides,and then the conductivity and other properties can be improved.Based on this,in order to improve the sensing performance,ZnO and its composite materials were prepared by electrospinning method,and used to immobilize enzyme to construct tyrosinase（Tyr）biosensor andβ-lactamase（PE）biosensor elements,so as to realize the detection of catechol andβ-lactam antibiotics.The specific research contents and results are as follows:（1）ZnO materials were prepared by electrospinning method,and the morphology and structure of ZnO were characterized by scanning electron microscopy（SEM）and X-ray diffraction（XRD）.The Tyr/ZnO/CS/GCE electrode was constructed by loading Tyr and used to detect catechol.The conditions were optimized by cyclic voltammetry（CV）and chronoamperometry（IT）.The results show that the reaction process of Tyr/ZnO/CS/GCE electrode is diffusion controlled.When catechol was detected,the linear detection range of catechol was 5～50μM,the minimum detection limit（LOD）was 1.9041μM,and the sensitivity was 26.6μA/m M,when Urea,Dopamine and Glucose were added,it still has good anti-interference and good cycle stability.（2）Cu-ZnO materials were prepared by electrospinning.The microstructure of Cu-ZnO was analyzed by SEM/FESEM,XRD,XPS and HRTEM.The Tyr/Cu-ZnO/CS/GCE electrode for catechol detection was constructed by loading Tyr,and the experimental conditions for catechol detection were optimized by CV.The results show that the addition of Cu obviously improves the properties of ZnO materials.The control step of Tyr/Cu-ZnO/CS/GCE electrode was diffusion control.When catechol was detected,the linear detection range was 2.5～50μM,LOD was 1.7542μM,and the sensitivity was 68.0μA/m M.The sensing performance of Tyr/Cu-ZnO/CS/GCE was better than that of Tyr/ZnO/CS/GCE electrode.When Urea,Dopamine,Glucose and L-ascorbic acid were added into the system,it still showed good anti-interference performance,and its cycle stability and preservation performance were better than those of Tyr/ZnO/CS/GCE electrode.（3）Ce O2-ZnO and Cu/Ce O2-ZnO materials were prepared by electrospinning method.The microstructure of Ce O2-ZnO and Cu/Ce O2-ZnO were analyzed by FESEM,XRD,XPS,HRTEM and SPV.Tyr/Ce O2-ZnO/CS/GCE and Tyr/Cu/Ce O2-ZnO/CS/GCE electrodes for catechol detection were constructed by loading Tyr.The results show that there are close heterojunctions in Ce O2-ZnO and Cu/Ce O2-ZnO materials,and the strong built-in electric field formed in the space charge region of heterojunction can facilitate the charge separation process.The control steps of the two electrodes were diffusion control,the linear detection range of catechol were 2.5～60 and2.5～50μM,LOD were 0.5459 and 0.9480μM,and the sensitivity were 59.6 and98.0μA/m M respectively.When Hydrogen peroxide,Glucose,Dopamine and L-ascorbic acid were added,the two electrodes showed good anti-interference performance,and the cycle stability and preservation performance were better than those of Tyr/ZnO/CS/GCE electrode.（4）HE/Ce O2-ZnO/CS/PE/GCE and HE/Cu/Ce O2-ZnO/CS/PE/GCE electrodes for the determination of penicillin G sodium were constructed by using Ce O2-ZnO and Cu/Ce O2-ZnO materials loaded with PE.Constant capacitance method（Con Cap）was used to optimize the experimental conditions for the detection of penicillin G sodium.The results show that HE/Cu/Ce O2-ZnO/CS/PE/GCE electrode has higher charge transfer efficiency.When the low concentration penicillin G sodium is tested,the corresponding detection range of HE/Ce O2-ZnO/CS/PE/GCE electrode was 5～80μM,the sensitivity was 0.9 and 0.2μA/m M,and the LOD was 3.2170μM;the corresponding detection range of HE/Cu/Ce O2-ZnO/CS/PE/GCE electrode was2.5～100μM,the sensitivity was 2.2 and 0.3μA/m M and the LOD was 2.0540μM.When the high concentration penicillin G sodium is tested,the linear detection range of HE/Ce O2-ZnO/CS/PE/GCE electrode was 10～1000μM,the sensitivity was 117.5 m V/m M,and the logarithmic detection range was 2～12m M;the corresponding linear detection range of HE/Cu/Ce O2-ZnO/CS/PE/GCE electrode was 10～1000μM,the sensitivity was 156.9 m V/m M,and the logarithmic detection range was 2～18 m M.In addition,two electrodes have good anti-interference and preservation performance,and only respond toβ-lactam antibiotics,but not to tetracycline antibiotics. |
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