Preparation Of Graphite Nanocarbon Material/Sol-Gel Composite Modified Electrode And Detection Of Environmental Hormones

In this study,electrical analysis technology have been mainly used to the determination of the target so as to realize the experimental goal of determination of the harmful subjects or biomacromolecules in the environment.The surface of the glassy carbon electrode has been modified with the novel nanomaterial by dispensing method or electrochemical deposition method.Then,the detection analysis of environmental hormone such as nonylphenol and bisphenol A has been studied using the modified electrode.The main studies are as follows:(1)?-Cyclodextrin functionalized graphite sol gel film modified electrode to detection bisphenol A: based on the large specific surface area ofgraphene,the excellent film-forming ability of sol-gel,the biodegradability and enrichment of cyclodextrin the modified electrode was prepared by using a graphene/sol-gel/?-cyclodextrin composite membrane(GNP/sol-gel/?-CD/GCE)to the detection of bisphenol A.The experimental results show that the doping of graphene,sol gel and ?-cyclodextrin improves the conductivity and enhances the peak current of bisphenol A.The amperometric current of the Gr/sol-gel/?-CD/GCE show a good linear relationshipto with the concentration of bisphenol A from 0.1 ?mol/L to 50 ?mol/L.The detection limit was calculated to be 25 nmol/L according to the IUPAC method(S/N = 3).(2)Preparation of graphene nano platelets,sol-gel,?-cyclodextrin and nano-gold composite film modified electrode(Au-NP/?-CD/sol-gel/GNP/GCE)by electrochemical co-deposition method to detect nonylphenol: To decorate graphene nano platelets(GNPs)with uniform and non-aggregated and well-distributed gold nanoparticles(Au NPs)as well as to improve the stability of GNPs on the electrode surface,an in situ co-electrodeposition procedure was developed in the mixture of sol-gel,?-cyclodextrin(?-CD),and gold precursors.On the Au NPs,sol-gel,and ?-CD composites based interface,voltammetry of nonylphenol was investigated on the surface of modified electrode.The enhanced oxidation current of nonylphenol was explained as a synergetic effect of graphene,uniformly distributed Au NPs,sol-gel,and ?-CD.After the optimization of the conditions,it was found that the oxidation peak current had a linear relationship with the concentration of nonylphenol from 0.01 to 1.0 ?mol/L,the linear equation was Ipa = 4.45 + 2.99 C,the linear correlation coefficient was 0.999,the sensitivity was 7.4 ?A/?mol/L,and the detection limit is 3.0 nmol/L(S/N=3).(3)Expanded graphite/carbon nanotubes(CNT@EG)prepared by CVD,doping CNT@EG composite film on the electrode to detect bisphenol A: vapor deposition deposition,in expanded graphite layer between the growth of carbon nanotubes,CNT@EG materials.With dripping CNT@EG on the bare glassy carbon electrode,CNT@EG electrode(CNT@EG/GCE)was prepared.A scanning electron microscope(SEM)and the electrochemical techniques were used to study the properties of CNT@EG/GCE.Choosing cyclic voltammetry to represent bisphenol A(hormone-like substances).The results show that with bare glassy carbon electrode electrode compared to EG/GCE and CNT@EG/GCE,CNT@EG/GCE to bisphenol A showed a biggest oxidation current.With the concentration of bisphenol A from 0.02?mol/L to 2?mol/L,and the oxidation peak current on CNT@EG/GCE showed a good linear relationship with concentration of bisphenol A.The detection limit was 5.0nmol/L according to IUPAC method(S/N=3).CNT@EG/GCE has a good stability and reproducibility.