Electrochemical Sensor Configuration Set And Applied Research Of Several Neurotransmitters

Using new materials, including organic polymer and graphene in construction of high sensitive and selective electro-chemical sensors for neurotransmitters. In this dissertation, several kinds of electro-chemical sensors based on sulfonic azo dye and graphene materials were fabricated, and the behaviors of electro-chemistry and electro-catalysis for dopamime (DA), uric acid (UA), acetaminophen (AP), L-tryptophan (Trp) and epinephrine (EP) on these modified electrodes were investigated in details. These studies may be of great importance not only in the field of biomedical chemistry and neurochemistry but also for diagnostic and pathological research. The thesis consists of four chapters and the author’s main contributions are as follows:1. By electro-polymerization methods, four kinds of poly (sulfonic azo dye) modified electrodes, including poly (new coccine)/CPE, poly (sunset yellow)/CPE, poly (zincon Sodium Salt)/CPE and poly(ponceau S)/CPE, were fabricated and their behaviors of electro-chemistry and electro-catalysis were investigated respectively. The spectral results and surface characteristics of modified CPE indicated the hydrazone functional groups in the poly (sulfonic azo dye) structure catalysed dopamine electro-chemical reaction, and sulfo functional groups could adsorb of dopamine to enhance the electrochemical properties of the modified electrodes.2. A facile electro-chemical sensor based on citrazinic acid (CA) functionalized graphene (CA-rGO) was fabricated. The composite film modified electrode exhibited excellent selectivity and sensitivity towards dopamine (DA) and uric acid (UA) detection, owing to the electro-catalytic effect of non-directional arrangement of rGO. Differential pulse voltammetry (DPV) was used to determine DA in the presence of UA. It was found that all of oxidation peaks of two species could be well resolved. The calibration curve for DA ranged from0.30to909μM with a detection limit of0.09μM (signal/noise=3). The constructed sensor has been employed to quantitatively determine DA and UA in real samples.3. Electro-chemical characterization of IDHP on poly (new coccine) was investigated by cyclic voltammetry and differential pulse voltammetry. This modified CPE exhibited excellent electro-catalytic activity towards the oxidations of IDHP. Well defined and separated oxidation peaks were observed by CV. Linear calibration plots for the oxidation of IDHP was obtained in the range of0.4x10-6~2xl0-5mol/L. Detection limits of IDHP was found to be1.0xlO-7mol/L. and next the interaction behaviour between IDHP and bovine serum album (BSA) was investigated by CV and DPV. The results indicated that IDHP could combine with BSA to generate non-electroactivity complexes, the binding number was2and the binding constant of1.00x1010L mol"1was obtained.