Preparation Of Electrochemical Sensors For Small Molecule Compounds Based On Nanomaterials

This thesis is divided into two parts, the first part is the electrochemical sensorsbased on the modified electrode and nanomaterials, which detect glucose anddopamine using the method of electrochemical analysis. Glucose and dopamine areimportant biological small molecules, which will cause a range of diseases.Therefore, it is important to detect these small biomolecules with an easy way inorder to prevent the disease.1. In this study, nickel foam was applied as the electrode materials, and Aunanoparticles were deposited on the nickel foam electrode surface byelectrochemical deposition. The glucose (GO) was oxidized on the foamed nickelelectrode surface, due to the catalytic effect of Au nanoparticles and foamed nickel.Under the optimum experimental conditions, the glucose was detected withdifferential pulse voltammetry. A good linear relationship with the concentration ofglucose from2.0×10-7M to1.0×10-5M and the detection limits as low as7.6×10-8M (3σ) were achieved. The as-prepared non-enzymatic sensor has potentialapplication value, which is simple preparation and preservation without specialconditions.2. A novel electrochemical sensor based on polythiophene/MWCNTs/AuNPswas built for the determination of dopamine. The catalytic action and synergisticeffect of polythiophene/MWCNTs composite and gold nanoparticles for dopamineresulted in a fast, sensitive, and selective electrochemical method for determinationdopamine. Under the optimum conditions, linear range for the detection of dopaminewas from1.0×10-8M to1.0×10-5M, while the detection limit was3.4×10-9M(3σ). It was showed that the modified electrode had a good selectivity, accuracy and low limits in a easier operation for dopamine.The second part is of an electrochemiluminescence (ECL) sensor based onCdSe quantum dots to detect o-aminophenol. Using CdSe quantum dots asluminescent materials, β-cyclodextrin as identification unit for its cavity structureelectrochemiluminescence (ECL) sensor was achieved to detect o-aminophenol.Under the optimum conditions, a good linear relationship with the concentration ofo-aminophenol from1.0×10-7mol·L-1to8.0×10-6mol·L-1and the detection limitsas low as2.3×10-8M (3σ) were achieved. Good selectivity and repeatability areadvantages of the sensor which is feasible.