Polyhydroxy Quaternary Ammonium‐Modified Magnetic Beads for Broad‐Spectrum Capture and Sensitive Detection of Pathogenic Bioaerosols

Bioaerosol transmission serves as a major route for the spread of respiratory infectious diseases, making the efficient enrichment and accurate detection of low‐concentration airborne pathogens crucial for early warning and infection control. However, the low abundance and susceptibility to activity loss of pathogens in aerosol samples often lead to false‐negative results with conventional detection methods. In this study, functionalized magnetic beads (PQ‐MBs) were constructed by simultaneously grafting multihydroxy and quaternary ammonium groups onto the bead surface via an amino‐epoxy ring‐opening reaction. The material utilizes the high‐density positive charges of the quaternary ammonium groups to achieve broad‐spectrum adsorption of negatively charged pathogens through electrostatic interactions, without requiring complex biological modifications or chemical conjugation. Efficient separation and enrichment can be accomplished simply with the aid of a magnetic field. Meanwhile, the introduced multihydroxy structure endows the material with favorable hydrophilicity and interfacial compatibility, promoting rapid pathogen desorption under gentle elution conditions while preserving their structural integrity and nucleic acid amplifiability. Experiments have shown that this system maintains high adsorption efficiency while effectively desorbing a variety of pathogenic microorganisms, thereby significantly improving the sensitivity of subsequent polymerase chain reaction (PCR). The integrated approach established in this work‐combining sampling, enrichment, and desorption‐provides effective technical support for the rapid on‐site detection of low‐concentration aerosolized pathogens and holds promising application prospects in environmental bio‐safety monitoring and infection control.