Description
Detection of neurotransmitters through voltammetry is a common technique in NeuroMEMS (neural microelectromechanical systems). Dopamine and serotonin are electroactive neurotransmitters and relatively easier to detect through electrochemical ways. Other non electroactive neurotransmitters such as glutamate, lactate acid, and gamma- Aminobutyric acid (GABA) are challenging to detect without modifying the electrode surface. Electrochemical methods, such as fast-scan cyclic voltammetry (FSCV), are used to detect electroactive neurotransmitters and molecules in-vitro. To detect non-electroactive molecules, must be reduced into electroactive molecules. Glassy carbon microelectrodes (GC) have shown to be a promising material in neuroscience, specifically electrochemistry, with a capability of detecting electroactive and non-electroactive species such as glutamate. In this work, we demonstrate immobilization of glutamate oxidase (GluOx) on a probe with a four-electrode array and subsequently using FSCV. We focus on some current strategies for glutamate probes immobilization on the electrochemical transducer's surface, such as covalent bonding, glutaraldehyde, bovine serum albumin (BSA), and GluOx reaction on the electrode surface for specific interaction with its corresponding glutamate target. Using glutaraldehyde, BSA, and glutamate oxidase, we could detect an electrochemical reduction of O2 to H2O2. The immobilization matrix of GluOx on the GC electrode acts as a barrier that allows the electrode to give supporting electrons. By functionalizing bare GC electrodes, we have shown the detection of glutamate, a non-electrode molecule. Through the chemical reaction with an enzyme happening at the surface of the electrode and cyclic voltammetry, we were able to show the chemical reduction of non-electroactive molecules.
