Me-N-C (Me= Fe, Co) Electrocatalysts with EDTA-Derived N for Dopamine Electrochemical Detectionpreferred

Abstract

Neurotransmitters are chemical transporters that exchange signals between neurons and other cells. Measuring their concentrations in vivo is a very challenging procedure, firstly because the extracellular concentrations of neurotransmitters are very low and can change rapidly and secondly because they co-exist with many electroactive neurochemicals in the brain, interfering the neurotransmitters detection. Dopamine (DA) is a catecholamine, modulating many parts of brain circuitry. Abnormal levels of DA are associated with neurological disorders such as schizophrenia, Alzheimer’s and Parkinson’s diseases. Herein, we synthesized low-cost electrocatalysts using a template-free synthesis method with ethylene diamine tetra acetic acid (EDTA)-nitrogen precursor, carbon substrate and Fe or Co nanoparticles. Both electrocatalysts were investigated towards dopamine oxidation reaction. In the figure below, the amperometric response curves of Co-kb-N /GCE (A) to continuous addition of 1 mM DA (red) and 10 mM DA (pink) are presented, with 1100 rpm in 0.1 M KOH (pH=13) at -0.05 and -0.15 V vs. Ag/AgCl, respectively. Additionally, plots of current versus DA concentration and the corresponding linear fitting after the addition of 1 mM DA (Bi) and 10 mM DA (Bii) solution are depicted. Co-kb-N exhibited the most promising behavior, with three linear ranges: 0.1- 0.41 mM, 1- 3.55 mM, 3.75- 4.74 mM and 0.11, 0.48, 2.58 mM limit of detection, as well as 871.4, 571.3, 105.7 μA mM-1 cm-2 sensitivity, with R2 0.99, 0.98, 0.95, respectively. Figure 1