Npy Selectivity on Methylene Blue Aptamer-Modified Microelectrodes

Abstract

Over the past 50 years, there has been a significant improvement in our understanding of neurotransmitters, especially in relation to depression, schizophrenia, Parkinson's disease, and Alzheimer's disease. However, little is known about how neuropeptides are released and work, and much of their activity is inferred through indirect observations. Since neuropeptides are non-electroactive molecules and are therefore challenging to detect, it is essential to develop an analytical approach for measuring them. The most prevalent neuropeptide in the brain is called neuropeptide Y (NPY), and it has been linked to a wide range of biological functions and diseases, including post-traumatic stress disorder (PTSD), depression, anxiety, obesity, alcoholism, mood swings, and eating disorders. There is currently no technology for measuring NPY in the brain with great temporal and spatial resolution. In order to comprehend the process in which NPY is engaged, we thus proposed the building of a biological sensor. This study focuses on affinity-mediated electrochemical techniques for NPY detection and measurement. In order to take advantage of the affinity between Pt and a thiol group in the aptamer structure, an aptamer—a short single-stranded DNA with high affinity by NPY—was connected to a Pt surface of a microelectrode. The aptamer was then conjugated to a redox molecule, such as methylene blue (MB), to boost the electrochemical signal and enable quick monitoring of NPY levels in real time. To find NPY in synthetic Cerebrospinal Fluid (aCSF), real-time methods including square wave voltammetry (SWV) and cyclic voltammetry were investigated. We were able to determine the concentration of NPY in aCSF (pH = 7.4) since MB produced a distinctive signal in both procedures. As the NPY molecules interacted with the aptamer, the MB electrochemical signal was altered, resulting in a "signal-off" sensor. With the aid of these findings, we were able to create a calibration curve that will serve as the foundation for further Fast Scan Cyclic Voltammetry (FSCV) experiments that will improve the temporal and spatial resolution of our studies. Recent studies have been directed towards the testing of the selectivity by measuring different neuropeptides and their selectivity towards the aptamer-modified microelectrodes.