Aptamer-Based Intelligent Magnetophoretic Microfluidic Platform with Weighted Signal Analysis for Sensitive On-Site Detection of Chloramphenicol

Abstract The rapid on-site determination of chloramphenicol (CAP) residues remains an important analytical challenge, requiring adequate sensitivity while maintaining operational simplicity and portability. Here, we developed a magnetophoretic microfluidic platform based on weight allocation (MMP-WA) for on-site CAP detection. Aptamer-mediated CAP recognition was translated into differential magnetic loading of polystyrene microspheres, generating distinct magnetophoretic behaviors within a customized self-driven linear microfluidic array. These particle-resolved signals were spatially classified into distinct magnetophoretic states and assigned class-specific weighting factors, enabling weighted decoding with enhanced signal discrimination and quantitative accuracy without complex biochemical signal amplification. A smartphone-based automated analysis system further enabled signal recognition and quantitative readout according to the predefined weighting factors. MMP-WA exhibited a linear response spanning more than four orders of magnitude, achieving over 4-fold higher analytical sensitivity and a 10-fold broader linear range than conventional enzyme-linked immunosorbent assay, while showing approximately 100-fold higher analytical sensitivity than lateral flow immunoassay. Through magnetophoretic signal classification and weighted signal analysis, MMP-WA provides a simple, portable, and sensitive strategy for rapid on-site CAP monitoring.