Fabrication of Aptamer-Modified Microelectrodes for Npy Detection in Artificial Cerebrospinal Fluid Using Methylene Blue As Electrochemical Signal Amplifier

Abstract

In recent years microelectrodes (ME) have been a great tool in the study of neuroscience. Microelectrodes are often used in neurotransmission research due to characteristics such as their small diameter, electrochemical capabilities, and compatibility with quick electrochemical procedures. Using methylene blue (MB) as an electrochemical signal amplifier allows us to assess adsorption of Neuropeptide Y (NPY) on the electrode surface in artificial cerebrospinal fluid (aCSF) with a pH of 7.4. Electrochemistry has a number of significant benefits over other methods of detection. One of these benefits is the ability to monitor a variety of molecules rather than only those that oxidize or decrease by changing the electrodes' material and altering their surfaces to provide selectivity toward the biomolecule of interest. In order to measure NPY using aptamer-modified microelectrodes with MB we first must prepare the microelectrodes by aspirating a platinum fiber into a quartz material and creating a connection. These are then cleaned electrochemically and characterized bare before being left in an aptamer solution to be modified. Then they are characterized again and left in a MB solution to complete the modifications. We were able to see the difference between the bare and modified electrodes during the characterizations as well as a constant peak of MB through the use of Square Wave Voltammetry (SWV) when characterized in aCSF which leads us to conclude that our method is successful in measuring and detecting different concentrations of NPY. We were able to measure NPY at varying concentrations ranging from 1 to 1000 pg/ml. This was observed as a reduction of the signal of the MB peak as the concentration of NPY is increased.