Smartphone-enabled molecularly imprinted paper-based sensor for dual-mode detection of diclofenac sodium in Milk, beef and water.

In this study, we proposed a novel dual-mode paper-based sensor that synergistically combines colorimetric and fluorescence detection for the rapid and sensitive quantification of diclofenac sodium (DFS) in fresh milk, beef, and water matrices. By integrating copper sulfide nanoflowers (CuS) with molecularly imprinted polymers (MIPs), the sensor achieves high specificity and catalytic efficiency, while europium nitrate polymer (EuPMs) enhance sensitivity through fluorescence quenching. The smartphone-enabled analytical platform provides rapid on-site quantification with simplified sample pretreatment, achieving detection limit of 0.007 μM and recovery rates of 95.3 %-114.4 % in real matrices. This innovative approach not only addresses the limitations of traditional methods but also provides a portable, cost-effective solution for monitoring drug residues in agri-food supply chain and agri-environment, bridging the gap between conventional laboratory analysis and field deployable testing.