Preparation Of Carbon-based Nanomaterials/Polymer Composite Film Modified Electrode And Its Application In The Detection Of Small Biomolecules

At present, the preparation of nanostructured electrochemical sensing interface inorder to improve the sensitivity and selectivity of detection is a hot research filed ofelectrochemical sensor. Carbon nanomaterials, such as carbon nanotubes, graphene,carbon nano quantum dots, with its unique physical and chemical properties have beenwidely studied and applied in electrochemical sensing. Organic polymer film with specialproperties such as containing active group of rich, stable quality and easy preparation,and can give the electrode interface, selective preconcentration, which can improve thestability, selectivity and sensitivity of the electrode, has received much attention in thefield of electrochemical sensor. Based on this, we prepared overoxidizedpolypyrrole/carbon nanomaterials by direct electrochemical method, poly-(L-His)/ERGOmodified electrodes, detailed studied of the physicochemical properties of compositefilms and ascorbic acid (AA), dopamine (DA), uric acid (UA), glucose (Glu)electrochemical sensing performance of small biomolecules. And on this basis, thenon-enzymatic sensor of glucose nano copper oxide/overoxidized polypyrrole/carbonnanomaterials composite films modified electrodes.The value of this reaserch is prepared by direct electrochemical carbon basednanomaterials/organic polymer composite film modified electrochemical sensor interfacesimplifies interface modification precedures, improve the stability. At the same time, bycombination of carbon based-nanomaterials and organic polymer films advantages in electrochemical sensors, improved analysis of related substances detection sensitivityselectivity.The main contents of are as follows:1. Overoxidized polypyrrole and graphene composite film modified electrode wasfabricated by direct electrochemical methods. The electrochemical behavior ofdopamine (DA) on the modified electrode was investigated by cyclic voltammatry (CV)and different pulse voltammetry (DPV). The result showed that the modified electrodeexhibited high electrocatalytic activity for the oxidation of DA. Under the optimalconditions, the liner calibration curves were5.0×108mol·L1~3.0×105mol·L1withthe detection is1.0×108mol·L1, R2=0.997.2. A poly-(L-His)/ERGO hybrid film modified electrode had been fabricated by usingcyclic voltammommetry. The electrochemical behavior of DA, UA and AA wasinvestigated, respectively. The results showed that the resulting modified electrodeexhibited excellent electrocatalytic activity toward the electrooxidation of DA and UAand had superior selectivity for the determination of DA, UA in the presence of mass AA.Under the optimum conditions, the liner calibration curves of3.0×107~3.0×105mol·L-1and5.0×107~3.0×105mol·L1with the detection is3.0×107mol·L-1and3.0×107mol·L1was obtained for DA and UA, respectively.3. A Nano-CuO/GCE was fabricated by using directly electrochemical depositionmethod. The results showed that modified electrodes exhibited strongly electrocatalyticactivity of glucose. Under the optimum conditions, the liner relationship betweencatalytic current and glucose concentration was in the range of2.0×107~5.0×104mol·L1. The sensitivity for the determination of glucose was173.6μA.mM-1anddetection limit of2.0×108mol·L-1.4. A Nano-CuO/ERGO/OPPy/CCE was fabricated by using one step electrochemicaldeposition technique. The electrochemical behavior and electrocatalytic activity for theoxidation of glucose was also investigated by cyclic voltammetric and amperometrictechniques in0.10mol·L–1NaOH solution. The results showed that the resulting modified electrode had high electrocatalytic activity for the oxidation of glucose andanti-interference performance to AA, DA, UA, L-Cys. Under the optimum conditions,the calibration curve was over the range of1.0×10–6~8.4×10–4mol·L–1respectivecy,with sensitivities of146.52μA·mmol–1.5. A novel method was developed to fabricate the nano-CuO, overoxidized polypyrroleand multi-walled carbon nanotubes (MWCNTs) thin films on electrodes byelectrochemical polymerization of pyrrole with MWCNTs, followed by electrodepositionof nano-CuO on the composite films. The composite films ofnano-CuO/MWCNTs-OPPy modified electrode was characterized by scanning electronmicroscopy (SEM) and the electrochemical behavior of glucose on this modifiedelectrode was also investigated in0.10M NaOH solution by cyclic voltammograms andamperometric. This modified electrode showed much higher electrocatalytic activity thanthe bare electrode towards oxidation of glucose. Under the optimum conditions, thecalibration curve of CV method was over the range of2.0μM to10.0mM with thedetection limit of0.40μM (3sb). The highest sensitivity for the determination of glucosewas63.69μA mM–1. The calibration curve of amperometry was over the range of0.20μM to2.0mM with the detection limit of0.05μM (3sb). The highest sensitivity for thedetermination of glucose was243.7μA mM–1. In addition, the modified electrode washighly resistant against poisoning the interference, such as AA, DA, UA and L-Cys.More importantly, this modified electrode can be used for the glucose detection in humanblood serum samples.