Optimized Electrochemical Sensor for Ochratoxin A Quantification in Coffee and Wheat Matrices.

Sensitive and selective ochratoxin A (OTA) detection in challenging food matrices (wheat, coffee) is achieved using a cost-effective electrochemical method. The approach utilizes commercial carbon black-graphite screen-printed electrodes (SPE CB-G) enhanced via modification with cetyltrimethylammonium bromide (CTAB). Adsorptive stripping differential pulse voltammetry (AdSDPV) parameters are rigorously optimized using central composite design (CCD), resulting in an optimal deposition time of 205 s and a CTAB concentration of 80 μmol L. The method achieves a limit of detection (LOD) of 1.39 ng mL and a limit of quantification (LOQ) of 4.20 ng mL in 0.2 mol L phosphate buffer (pH 7.0) solution. In roasted and ground Arabica coffee (), the method demonstrates a LOD of 2.70 ng mL and a LOQ of 8.20 ng mL, with recovery rates ranging from 94.64 to 109.86%, compliant with key regulatory standards. The presence of CTAB minimizes the matrix effects and ensures reliable and reproducible results. This optimized SPE-based sensor offers a practical and efficient alternative to conventional methods for routine food safety monitoring.