Design and Development of a Miniaturized Electrochemical Platform for Sensitive Detection of Dopamine

Traditional electrochemical sensing systems are hindered by high cost and limitations in portability, which collectively restrict their applicability in point-of-care (POC) diagnostics and continuous monitoring. This study reports the design, development, and experimental validation of a portable, low-cost potentiostatic measurement platform tailored for electrochemical analysis. The custom-built system supports a standard three-electrode configuration and executes both square wave voltammetry and cyclic voltammetry, enabling robust investigation of redox processes. The system reliably maintained a stable potential between working and reference electrodes and accurately recorded current responses, confirming its functional integrity. Laser-induced graphene (LIG) was employed as a nonenzymatic carbon-based catalyst for the oxidation of dopamine. The platform demonstrated excellent analytical performance for dopamine detection, achieving a linear detection range from 3 to $100~\mu $ M, with a limit of detection of $0.176~\mu $ M, a limit of quantification of $0.588~\mu $ M, and a sensitivity of 48.1 ( $\mu $ A/ $\mu $ M)/cm². Further evaluation of selectivity, stability, and reproducibility confirmed that the LIG-based sensor effectively discriminates between interfering analytes while maintaining consistent performance across repeated measurements. Overall, the developed platform represents a versatile, affordable, and accessible solution for electrochemical sensing, with potential for deployment in decentralized settings for POC diagnostics, field-based environmental monitoring, and wearable biosensing applications.