Detection of antibiotic sulfamethoxazole residues in milk using a molecularly imprinted polymer-based thermal biosensor
Margaux Frigoli, Joseph W. Lowdon, Thomas J. Cleij, Hanne Diliën, Kasper Eersels, Bart van Grinsven
Abstract
Antibiotic resistance is a growing concern, partly due to inadequate inspections in the food safety chain. The accumulation of antibiotics like sulfamethoxazole (SMX) in animal products contributes to the rise of resistant microorganisms, posing a global health challenge. This work focuses on developing a thermal sensor to quickly and affordably detect SMX residues in milk samples. Molecularly imprinted polymers (MIPs) were synthesized and immobilized on an aluminum chip to measure thermal changes using the heat-transfer method (HTM). The sensor's detection limit in calcium chloride solutions was 261 ± 12 pmol L −1 , well below regulatory limits for sulfonamides in dairy. The sensor also showed good selectivity when tested against antibiotics from different classes, and good performances in spiked milk samples. These results indicate that the thermal sensor provides a sensitive, low-cost alternative for detecting sulfamethoxazole traces in dairy products, contributing to improved food safety. • A thermal biosensor is developed to detect sulfamethoxazole residues in milk. • Molecularly imprinted polymers (MIPs) are materials used as recognition elements. • The sensor detects sulfamethoxazole residues in milk samples without pretreatment. • The device's detection level is suitable for industrial applications. • This low-cost sensor could improve food safety and reduce antibiotic resistance.