AFM and Electrochemical Analysis of Npy Using Npy-Specific Aptamer-Modified Gold Electrodes

Abstract

Measurements of neurotransmitters are important to understand some mechanisms of how they are released off the cell. Neurotransmitters and neuropeptides are chemical signals in the brain that produce responses or functions throughout the organism. These biomolecules can be measured with gold (Au) electrodes because it is a ductile and malleable metal that can detect small changes and can be easily modified. In this work, we use NPY-specific aptamer to modify the electrodes to take the advantage of the binding with NPY molecules that produces conformational changes. Those modifications and detection can be monitored using Electrochemical Impedance Spectroscopy (EIS), to understand the adsorption properties of molecules that stick to the surface of the electrode and Atomic Force Microscopy (AFM) to measure the topography of the electrodes before and after the aptamer modification. AFM results showed small changes on the surface of the Au electrodes with the different modifications due to the roughness of the surface. Electrochemical results showed that the capacitance of the gold electrode decreases at higher concentrations of NPY. The results obtained give us a better understanding of the use of these techniques for the monitoring of biomolecules.