| This paper summarized the research status of the modified electrode, nano-array electrode and their application in immunoassay. The 1, 6-Hexanedithiol modified electrode(HDT/Au),multi-walled carbon nanotube modified glassy carbon electrode (MWNTs / GC) and 2 -dimensional gold nano-disk electrode (2DNEEs) were made in this paper,and their performance was characterized. The paper designed experiments to optimize various factors of Horseradish peroxidase catalytic system. By using four kinds of electrodes to detect the concentration of HRP and comparing the detection results, the paper got electrodes which were fit for the detecting system. Taking enzyme-linked voltammetry to detect rabbit IgG antigen and aflatoxin B1, the detection achieved a good results.With 0.1 M 1, 6-Hexanedithiol as a modified solution, the gold disk and wire electrodes wich diameter were 3mm and 0.5mm were modified respectively. By using self-assembly method, the HDT modified layer was formed on the surface of gold electrode. The performance was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The results showed that HDT modified layer hindered electron transfer of the redox reaction of K3Fe(CN)6/ K4Fe(CN)6; along with the modified time extension, this resistance was stronger and stronger. The glassy carbon electrode was modified by 0.1%Nafion-1 mg/mLMWNTs. The performance was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The MWNTs modified layer speeded electron transfer of the redox reaction. Taking track etching polycarbonate membrane as the template, a certain intensity of continuous gold nanowire arrays was made by chemical deposition method. The length of nanowire arrays was 6μm; pore density was (15) 108 /cm2,and the diameter was 100 nm.The 2DNEEs was characterized by cyclic voltammetry and SEM. The results showed that the redox reaction of K3Fe(CN)6/ K4Fe(CN)6 on the surface of 2DNEEs was controlled by the linear diffusion.The O-phenylenediamine-H2O2-HRP catalytic system was studied to get optimum response parameter. The reasult showed that when temperature was 30℃, pH 5, OPD: H2O2 2.8, the reaction time 1 h, the catalytic effect of HRP for the substrate reaction was the best. The paper studied the electrochemical characteristics of OPD-H2O2-HRP catalyst System. Taking gold disk electrode, HDT/Au, 2DNEEs and MWNTs / GC as the working electrode, HRP got detected. The linear range of the detection of gold disk electrode was 6×10-11-2×10-9 g/mL, and the detection limit was higher than other two electrodes. The linear range of the detection of HDT/Au was 2×10-11-2×10-9 g/mL, and the detection limit can reach 1×10-11 g/mL. The Linear range of the detection of gold nano-array electrode was 2×10-11-5×10-10 g/mL, and the detection limit can also reach 1×10-11 g/mL. The linear range of the detection of MWNTs/GC was 1×10-125×10-10 g/mL. The detection result of HDT / Au was better.Taking OPD-H2O2-HRP catalyst system as a basis, by using miniature three-electrode system, the rabbit IgG antigen and aflatoxin B1 got detected by enzyme-linked voltammetry. The detection linear range of rabbit IgG antigen was 1×10-7-3×10-7g/mL, and the detection limit can reach 5×10-8 g/mL. Simultaneously, the detection Linear range of aflatoxin B1 was 1×10-10-3×10-8 g/mL, and the detection limit can reach 5×10-11 g/mL. Compared with most reported in the literature, the detection limit of this experiment was lower.
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