Measurement of Neuropeptide Y By Square Wave Voltammetry Using Aptamer-Modified Platinum Microelectrodes and Methylene Blue
Authors: Vazquez Yolimar , Cunci Lisandro , Fernandez-Vega Lauren , Melendez-Rodriguez Dorian Enid 
Published: November 2022

In comparison to other methods of detection, electrochemistry offers a number of major advantages that make it the superior choice. One of these advantages is the capacity to monitor a wide variety of molecules, as opposed to just those that oxidize or deplete, by modifying the electrodes' surface areas and changing the material that makes up the electrodes in order to provide selectivity toward the biomolecule that is of interest. For more than three decades, the method known as Fast Scan Cyclic Voltammetry (FSCV) has been regarded as the method of choice for assessing neurotransmitters in animal models both in vitro and in vivo. It is important to create a unique method for measuring neuropeptides and other biomolecules in order to make use of long-term implants that have been approved by the FDA, such as electrodes used in deep brain stimulation (DBS). This research focuses on the use of electrochemical methods to biological applications, such as Square Wave Voltammetry (SWV) and Cyclic Voltammetry (CV). These methods allow researchers to detect biomolecules with a greater degree of accuracy. We investigated a variety of electrical devices for monitoring and detecting neuropeptide Y (NPY) using SWV and CV. For the purpose of NPY detection, we made use of platinum microelectrodes in conjunction with SWV and CV. Research on neurotransmission makes frequent use of microelectrodes because of their small size, electrochemical characteristics, and compatibility with quick electrochemical processes. Due to the precision and specificity offered by electrochemical techniques, we were required to develop a real-time technique in order to quantify biomolecules that were transported into the artificial cerebrospinal fluid (aCSF). This technique included the use of CV and SWV, both of which are examples of techniques that fall under the real-time category. The idea behind using aptamer-modified microelectrodes with methylene blue (MB) as a redox probe for the detection of NPY by SWV and CV is that the oxidizing potentials recorded by SWV may be utilized to evaluate the probe. This is the logic behind the use of these aptamer-modified microelectrodes. In order to conduct the test, an aCSF with a pH of 7.4 was used. It was essential to investigate SWV in space and time at NPY adsorption potentials and watch as MB was oxidized. For the purpose of studying SWV using platinum microelectrodes, we analyzed NPY with an aptamer that has been modified with MB. As a result of the fact that we were able to see a stable signal of MB throughout the characterizations, we have come to the conclusion that the strategy that we are utilizing for the modification of the aptamer is an effective one. In addition to this, we were successful in measuring NPY in a range of concentrations through the MB signal observed in the SWV. During the measurement of NPY we were able to see a decrease in current seen in the electrochemical signal of MB as we augmented the concentration of the neuropeptide. This enabled us to do a calibration curve that will be utilized for further measurements.