Constructon Of Novel Electrochemical Immunosensor And The Studies On The Determination Of Polycyclic Aromatic Hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants (POPs) widely present in the environment, many which are carcinogenic, teratogenesis and mutagenicity.1-Pyrenebutyric acid (PBA). one of PAHs derivatives and anthracene are harmful for human being and other flora and fauna. Therefore, it is of necessary to develop a sensitive, rapid and cost-effective method for PAHs detection. As an efficient trace analysis method, electrochemical immunosensor possesses the merits of high sensitivity, quick analysis, strong selectivity and simple structure, etc. However, few researches have been concentrated on utilizing electrochemical immunosensor to monitor PAHs and its derivatives up to now. Further investigations should be carried out for the electrochemical immunoassay for small molecules of PAHs.1-Pyrenebutyric acid (PBA) and anthracene (AN) were chosen as the examination objects in this paper. Graphene (GS), chitosan (CS), ionic liquid, nanoAu and ferrocenecarboxylate (Fc-COOH) were chosen as the modified materials. Three sensitive and specific electrochemical immunosensor were constructed. The modified sensor interface is taken as the sensitive element. Then the construction process of the immunosensor is described by electrochemical means such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), etc. The quantitative analysis for PBA and AN was realized according to the variation of the electron transfer after the immunoreaction between antigen and antibody on the sensing interface detected by differential pulse voltammetry (DPV) and EIS. Accoding to the research of the the electrochemical amperometric immunosensor and the electrochemical impendence immunosensor we explore new methods for polycyclic aromatic hydrocarbons rapid detection.A simple, highly sensitive, and label-free electrochemical amperometric immunosensor was developed based on graphene (GS) and chitosan (CS) composites and nanoAu modified glassy carbon electrode for the determination of PBA. The graphene and chitosan composite which has good electron transfer ability and large specific surface area were used as platform. The nanoAu which has prominent biocompatibility and primarily excellent adsorption were used to immobilize PAHs antibody (anti-PAHs). Under optimized conditions, the amount of immobilization of antibody was significantly improved on the modified electrode, resulting in amplification of the electrochemical signal for PBA detection. Because of the poor conductivity of the antibody-antigen immunocomplex, the current response of the proposed immunosensor decreased linearly with increasing concentration of PBA. The linear response of the immunosensor for PBA detection was at two ranges of concentrations from0.001to10and from10to200ng/mL with a detection limit of0.001ng/mL. The regression equation was ip1(μA)=0.105CPBA (ng/mL)-65.485with a correlation coefficient of0.9994and ip2(μA)=2.2218CPBA (ng/mL)-87.262with a correlation coefficient of0.99, respectively. Moreover, the proposed immunosensor had excellent selectivity and reproducibility.A highly sensitive, stable and label-free electrochemical immunosensor for the detection of1-pyrenebutyric acid (PBA) which was based on graphene (GS), chitosan (CS) and ionic liquids (1-butyl-3-methylimidazolium tetrafluoroborate,[BMIM]BF4, ILs) composites modified glassy carbon electrode (GS-CS-IL/GCE). The morphology of the GS-CS-ILs composites film was characterized by the transmission electron microscopy (TEM). The electrochemical behavior of the modified electrode and the electrochemical properties of the immunosensor were studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in detail. Under optimized conditions, the immunosensor showed a wide linear range and low detection limit. The amperometric response decreased with increase of the PBA concentration and was proportional to the PBA in the range of0.01to5ng/mL and5to150ng/mL, respectively. The regression equation was ip1(μA)=1.6482CPBA (ng/mL)-89.606with a correlation coefficient of0.9994and ip1(μA)=0.1837CPBA (ng/mL)-81.892with a correlation coefficient of0.9976, respectively. The detection limit was estimated to be0.01ng/mL based on a signal to noise ratio of3.An electrochemical impedance spectroscopy (EIS) immunosensor for the detection of AN was developed by immobilizing antibody through nanoAu. Graphene (GS). chitosan (CS). ionic liquid (ILs) and ferrocenecarboxylate (Fc-COOH) were combined together to prepare a new type of composite for the modification of glassy carbon elevtrode. The construction process of the immunosensor is described by electrochemical means such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), etc. The results shows that the plot of increased electron transfer resistances (Rets) against the logarithm of PBA concentration is linear over the range from0.001to30ng/mL with a detection limit of0.001ng/mL. The regression equation was ΔRet=935.21logc+3932.3with a correlation coefficient of0.9908. The selectivity and accuracy of the proposed EIS immunosensor were evaluated with satisfactory results.