Selective Electrochemical Sensor Using Screen-Printed Carbon Electrode (SPCE) for Dopamine Detection in Neutral Condition

A selective electrochemical sensor for detecting dopamine (DA) has been studied using a screen-printed carbon electrode (SPCE). The performance of SPCE was characterized using cyclic voltammetry at pH 7.0 in 0.1 M phosphate buffer solution. The measurement was done in a potential range of − 7.5 to 1 V at room temperature. The effect of DA concentration and scan rate was observed. The result showed that DA can be detected specifically by looking at its reduction peak signal at a potential of − 0.11 V, i_pc = − 52.13 μA. The signal of DA was monitored without any interference signals from ascorbic acid, glucose, uric acid, paracetamol, and urea. The obtained calibration curve, which represents various concentrations of DA as a function of peak current, followed the linear equation i_pa = 3.484 + 0.413x with R2 = 0.992 and i_pc = −2.741 − 0.267x with R² = 0.985. The limits of detection and sensitivity of SPCE for DA detection were 0.030 μM and 8.107 μA.mm ^-2.μM – 1, respectively. The effect of scan rate demonstrated a diffusioncontrolled behavior from the reaction between SPCE and DA. The repeatability study of SPCE showed an increase in the peak current value. This is due to DA poisoning, resulting in less precision of repeated measurements.