Preparation And Application Of Nanomaterials Modified Neurotransmitters Electrochemical Sensors

ObjectiveChange the levels of neurotransmitters in the human body was closelyrelated to human health, when the concentration deviates from the normal levelmay cause some diseases, such as Parkinson’s disease, Schizophrenia,Epilepsy, Huntington’s chorea and Depression. Thence, a rapid, low-cost,sensitive and selective method is strongly required to satisfy real application forclinical diagnosis and pathological analysis. Recently, electrochemical sensorsdue to its good sensitivity, selectivity, simple equipment, short cycle analysis,etc., are widely used to detect neurotransmitters. In this study, we first preparedGraphene/Tetraphenylboron-Dopamine modified graphite electrode, graphene/chitosan nanocomposite modified carbon paste electrode and ZnO nanopa-rticles modified coated wire polyvinyl chloride membrane γ-aminobutyric acidselective electrode to determine dopamine and γ-aminobutyric acid in biologicalsamples respectively, laying the foundation for the further development ofelectrochemical determination of neurotransmitter.MethodsAssociation complex formed with dopamine hydrochloride and sodiumtetraphenylborate as electrochemically active material, prepared Graphene/Tetraphenylboron-Dopamine modified graphite electrode; Preparation ofgraphene/chitosan nanocomposite by one-step, and modified it on the surface of carbon paste electrode, with the above-mentioned two electrodes todetermination of dopamine content in human urine. Association complexformed with two nitrogen philippine iron complexes and γ-aminobutyric acid aselectrochemically active material, prepared ZnO nanoparticles modified coatedwire polyvinyl chloride membrane γ-aminobutyric acid selective electrode todetermination of γ-aminobutyric acid content in germinated brown rice.ResultThe linear range for dopamine was successfully determined from1×10-4to1×10-10mol/L with Graphene/Tetraphenylboron-Dopamine modified graphiteelectrode. The detection limit was estimated to be7.39×10-11mol/L. Using thestandard addition method to detect dopamine levels in human urine, therecovery was98.3%to102.3%; The linear range for dopamine wassuccessfully determined from1.0×10-4to2.0×10-7mol/L with graphene/chitosan nanocomposite modified carbon paste electrod. The detection limitwas estimated to be9.82×10-8mol/L. Activity of the electrode only decreased7.4%after30days. Using the standard addition method to detect dopaminelevels in human urine, the recovery was98.7%to103.1%; The ZnOnanoparticles modified coated wire polyvinyl chloride membrane γ-aminobutyricacid selective electrode showed Nernst response for γ-aminobutyric acid with aslope of61mV/pC in the concentration range from8.9×10-7to1.0×10-1mol/L.The detection limit was estimated to be6.2×10-7mol/L. The electrode can beused to used to determine the concentration of γ-aminobutyric acid in the brownrice, the results got from detection were in conformity with spectrophotometerdetermination.ConclusionIn this research, we prepared Graphene/Tetraphenylboron-Dopaminemodified graphite electrode, graphene/chitosan nanocomposite modifiedcarbon paste electrode and ZnO nanoparticles modified coated wire polyvinyl chloride membrane γ-aminobutyric acid selective electrode. These sensorshave excellent selectivity, sensitivity, reproducibility, repeatability, stability andwide linear range. Successfully applied to the determination of neurotransm-itters in actual samples. Provides a theoretical basis for the further develop-ment of nanoelectrochemical determination of neurotransmitter.