SCREENING OF FABRICATION PARAMETERS FOR A LOW-COST MOLECULARLY IMPRINTED POLYMER (MIP)-BASED SENSOR FOR SULFAMETHOXAZOLE DETECTION

Abstract

The presence of sulfamethoxazole (SMX) residues in dairy products poses serious public health concerns, necessitating the development of low-cost and field-deployable screening instruments. While molecularly imprinted polymer (MIP)-based electrochemical sensors have shown promise selectivity for antibiotic detection, little attention has been paid to the screening of fabrication factors that have a significant impact on sensor performance. As a result, this research focuses on the screening of the critical fabrication parameters for a low-cost MIP-modified screen-printed carbon electrode (MIP/SPCE) platform for SMX detection. Cyclic voltammetry was used to assess the impact of carbon ink type (water-based versus solvent-based), stencil type (mesh stencil versus plotter cutter stencil), and MIP deposition volume (5 µL and 10 µL) on the electrochemical performance of the sensor. The MIP was synthesized by bulk polymerization and analyzed with scanning electron microscopy (SEM), which confirmed the successful creation of SMX-specific binding sites. Electrochemical screening findings showed that solvent-based carbon ink and plotter cutter stencils produced SPCEs with lower resistance (200-400 ?) and well-defined redox peaks than their equivalents. Furthermore, a 5 µL MIP deposition volume exhibited optimum electron transport properties, providing a larger anodic peak current than thicker MIP layers. These findings emphasize the importance of fabrication parameter selection in obtaining consistent and sensitive MIP/SPCE performance. The improved manufacturing structure provides a solid platform for the future development of low-cost electrochemical sensors designed for routine antibiotic residue detection in food safety applications.