Dopamine sensing in artificial neurons

Abstract

Dopamine is a key molecule in neurotransmission, that is produced in the substantia nigra, ventral tegmental area, and hypothalamus of the brain. Dysfunction of the dopamine system has been implicated in different nervous system diseases. Hence, a sensitive and selective method of detection is important for the early diagnosis of diseases related to abnormal levels of dopamine. More importantly, in neuron cells, dopamine receptors do not work alone. It recognizes dopamine, which eventually triggers action potential and the release of dopamine in the vesicles. Research methods have shown limitations in the integration of other elements into the sensor. As such, this project aims to create a sensor that is flexible and able to integrate elements like a Resistive Random Access Memory and a Heater for Hydrogel to release Dopamine, to create a system similar to that of a neuron cell. Graphene Oxide and Carbon Nanotube were synthesised to various ratios and used on the ends of a working electrode to detect dopamine in the electrochemical sensor. These materials were characterised using Amperometry to determine their sensitivity towards the presence of dopamine. Samples of Uric Acid, Dopamine and Ascorbic Acid were used to mimic the human body’s biological fluids to test the selectivity of the sample material, using Cyclic Voltammetry. The balance between high sensitivity and selectivity is the determining factor for the best material to be used to sense dopamine in this report.