Joshua Reyes Morales, Luis López Gonzalez, Nilka M. Rivera Serrano, Miraida Pagan Castillo and Lisandro F. Cunci Perez
Dopamine (DA) plays important roles in the neurological system. Alteration in DA transmissions trigger neurological disorders such as Parkinson’s disease, Alzheimer and schizophrenia. Environmental neurotoxins such as heavy metals are being related to target dopaminergic systems. Electrochemical Impedance Spectroscopy (EIS) is a technique where an electrochemically active reaction can be studied by a constant applied potential, chosen depending on the reaction to study, and measuring the current at different frequencies, typically between 10 Hz and 1 MHz. The results obtained are used to find an electrical circuit that could be equivalent to the surface of the electrode that can explain the molecular interactions. Platinum Microelectrodes (PtMEs) plays an important role in this process because of its conductivity and kinetics in an electrochemical process, allowing good measurements in EIS. This electrochemical method could be a possible alternative for detection methods to study neurological disorders. To determine this, five potentials were chosen from -0.6 to 0.2 V vs Ag|AgCl to detect dopamine at five different concentrations (100nM – 2000nM). The PtMEs were prepared by aspirating a Pt wire of 25 µm into glass capillaries. Our results show that the capacitance of the microelectrodes surface increase due to the dopamine concentration increase. The results confirm dopamine capacity to be detected at very low concentrations and frequencies up to 10KHz, when using PtMEs.