Fabrication And Study Of Two Kinds Of Electrochemical Sensors Based On Dopamine Autopolymer

Dopamine(DA)is an important catecholaminergic neurotransmitter,which plays an important physiological role as a chemical messenger in mammalians.Recent research shows that dopamine can self-polymerize at weakly alkaline condition and spontaneously form a layer of multifunctional biocompatible polydopamine(PDA)on virtually any surface.Currently,the electrochemical sensors fabricated by the self-polymerization of dopamine have become a hot research.With the rapid development of nano-materials,nano-materials have been used in the fabrication and research of the electrochemical sensors.The nano-materials’introduction can further improve the performance of the electrochemical sensors.In this article,there are two kinds of new electrochemical sensors which are based on dopamine autopolymer,graphene oxide(GO),nano-materials and so on.The main contents are as follows:1.The glassy carbon electrodes were used as substrates.We reported a new multilayers film glucose non-enzyme electrochemical sensor which used the(Cu/PDA)covalently assembled on the glassy carbon electrode layer by layer alternately.The glucose electrochemical sensor used the coordinated reaction and the reductive reaction.The electrochemical sensor had a good function of catalytic oxidation of glucose in alkaline medium.In this study,to explore the sensor’s performance,the UV-vis,electrochemical impedance analysis(EIS),cyclic voltammetry(CV)and amperometric i-t curve were used to test multilayer membranes electrode.The research showed that the sensor had a wide the detection range,good stability,reproducibility,selectivity.The sensitivity could be controlled by the layers.This electrochemical sensor could be used to detect the actual sample.2.First of all,preparing the PDA@AuNPs core-shell nanocomposites;Then,dropping the mixed solution of the PDA@AuNPs and GO on the surface of glassy carbon electrode;Finally,a new hydrazine hydrate electrochemical sensor was fabricated.This hydrazine hydrate electrochemical sensor had a good function of catalytic oxidation of hydrazine.Compared with the bare glassy carbon electrode,this hydrazine hydrate electrochemical sensor reduced the oxidation potential of the hydrazine hydrate and increased the oxidation peak current.Diffusion coefficients were determined by chronoamperometry.This sensor was applied to test the actual samples.3.This preparation method was the same way as the third chapter.This sensor was used to test the nitrite.To explore the sensor’s performance,the cyclic voltammetry,different pulse voltammetry(DPV)and amperometric i-t curve and so on were used to test the modified electrode.The research showed that the sensor had a wide the detection range,good selectivity and stability.The liner range for determination of the sodium nitrite was 2μmmol/L-2.5 mmol/L.