LOW-COST ELECTROCHEMICAL SENSORS FABRICATED FROM 3D-PRINTED PLA/GRAPHITE FILAMENTS FOR THE DETECTION OF DOPAMINE

The voltammetric analysis of dopamine is crucial due to its role in treating nervous system disorders like Parkinson's, schizophrenia, and ADHD. As a neurotransmitter, dopamine influences motivation, reward, cognitive and motor functions, and emotional regulation. [1] This work aimed to develop sustainable, low-cost 3Dprinted sensors for the detection of dopamine. The electrodes were fabricated using a conductive paste composed of polylactic acid (PLA) and graphite in a 40:60% (w/w). The electrodes were polished with 2000-grt. The impact of pH on the oxidation process of dopamine was assessed using a BR buffer solution (0.1 mol L⁻¹) across a range of pH values from 2.0 to 10.0, with pH 4 identified as the optimal condition. Additionally, the electroactive area of the working electrode was determined through cyclic voltammetry using [Fe(CN)₆]³⁻/⁴⁻ 2.5 mmol L⁻¹, yielding an area of 4.84 cm². A method using differential pulse voltammetry was optimized with an amplitude of 40 mV and a step potential of 3 mV. This optimization resulted in a linear working range of 2.0 to 10.0 µmol L⁻¹, showcasing excellent analytical performance. The method exhibited a relative standard deviation of less than 4% and demonstrated high accuracy, with recovery percentages ranging from 91% to 107% in the detection of the analyte in samples of the tap water, urine, saliva, and formulation pharmaceutical. Furthermore, the sensor displayed significant resistance to interference from other drugs and compounds commonly encountered in vivo analyses, underscoring its suitability for electroanalytical applications and its promising potential.