Electrochemical platform based on gold leaf electrode for simultaneous detection of multiple pathogens in the meat food matrix

We presented a novel multiplex electrochemical platform for the simultaneous detection of Escherichia coli , Salmonella Typhimurium , and Salmonella Enteritidis . The sensor platform was fabricated by hot lamination of 24-karat gold leaf onto PVC adhesive sheets and patterned via laser ablation. It included three aptamer-functionalized working electrodes, one counter, and one correctional electrode. The correctional electrode was introduced as a blank electrode (without aptamer immobilization), undergoing the same surface treatment and blocking steps, allowing effective compensation of background and matrix-induced signals. Surface blocking was performed using a 6-Mercaptohexanol (MCH) monolayer. Electrochemical impedance spectroscopy (EIS) was used for characterization. Detection was validated in phosphate-buffered saline and complex meat homogenate samples. The total test time was 20 minutes of incubation per sample, followed by EIS measurement. The biosensors achieved detection limits below 10 CFU/mL and a linear range of 10 1 –10 5 CFU/mL for all target pathogens. No false positives were observed with control bacteria. Recovery values from 79.61% to 121.97% in real samples confirmed the platform’s reliability. This work demonstrates a sensitive, specific, and reproducible method for multiplex pathogen detection in complex food matrices. • Multiplex electrochemical aptasensor for simultaneous bacteria detection • Novel sensor configuration with correctional electrode compensating matrix effect • Simple, low-cost fabrication using gold leaf electrodes with laser patterning • Detection of E. coli , S. Typhimurium , S. Enteritidis in complex food meat matrix • High biosensor selectivity with achieved detection limits below 10 CFU/mL • Validated in meat samples, enabling multiplex, single-measurement detection