Conductive Polymers Modification for Carbon Fiber and Platinum Microelectrodes for the Measurement of Neuropeptide Y

Abstract

Currently, one of the approaches in neuroscience research is the analysis and understanding of neurochemical behaviors. This is a great challenge since, although neurotransmitter measurements have been possible, these techniques have limitations, among which are the selectivity, sensitivity, and temporal resolution of the measurement. This work seeks to improve the Electrochemical Impedance Spectroscopy (EIS) technique using a Carbon Fiber Microelectrode and a Platinum Microelectrode for measurement with a conductive polymer modification of Pyrrole and Aniline. The EIS technique allows the measurement of the interaction of molecules in a solution and the surface of the electrode. The modification with conductive polymer is carried out since it is biocompatible, and having a load causes the selectivity to increase and, in turn, its sensitivity, in addition to being modifiable according to the application. Our objective is to find the optimal conditions for the modification of the surface of the microelectrode with the conductive polymers for use with EIS by measuring different neurotransmitters to study and understand its release mechanism and then be able to measure different concentrations. Our neuropeptide of interest is Neuropeptide Y (NPY) because it is related with many processes in the human body as regulation of appetite, stress, and diseases as Alzheimer and Parkinson disease. For conductive polymer modification we used 0.5M Pyrrole and Aniline in 0.5M H2SO4. Cyclic Voltammetry (CV) is applied to carry out the electropolimerization with 1 cycle per depositions 3 times. We used two solutions of ACSF (artificial cerebral-spinal fluid) one of them mixed with 10pg/ml of NPY and the other one without NPY to study the current behavior. SEM and EDS were used to study the morphology. As results for ACSF and ACSF-NPY we observed an increased in current at the first electropolymerization and a decreased after the second electropolymerization for CV.