A point-of-care SERS-based microdevice for multi-pesticide poisoning diagnostics towards first aid scenarios

Public concern regarding mixed pesticide poisoning involving chlorfenapyr has highlighted the urgent need for effective point-of-care diagnostics (POCD) to facilitate timely clinical rescue. This study presents a novel surface-enhanced Raman scattering (SERS)-based microdevice for the rapid identification and quantification of chlorfenapyr, lufenuron, and emamectin benzoate in human serum and urine for first aid scenarios. We developed a multifunctional sensor utilizing a porous cellulose ester (MCE) membrane modified with zeolitic imidazole framework-67 (ZIF-67) and gold concave rhombic dodecahedra (Au CRDs), creating an Au CRDs@ZIF-67/MCE composite that serves as both a SERS-active substrate and a sorbent. Assembled in a 24-well plate, this microdevice enhances enrichment selectivity and efficiency through a “1+1 dual-mode separation” effect, while the concave sharp tips of Au CRDs significantly boost SERS sensitivity. The correlation between SERS intensity and logarithmic concentration yielded R-values between 0.911 and 0.986, with detection limits from 0.16 ppb to 2.71 ppb, demonstrating clinical applicability. This microdevice analyzed patient bio-samples in 5 min, demonstrating both practicality and accuracy, as results closely aligned with those obtained from routine chromatography. Importantly, the detection process requires no sample preparation, underscoring its potential as a high-efficiency, user-friendly POCD assay for multi-pesticide poisoning in first aid scenarios.