Bacterial pathogens pose high threat to public health worldwide. Different types of nanomaterials have been synthesized for the rapid detection and elimination of pathogens from environmental samples. However, the selectivity of these materials remains challenging, because target bacterial pathogens commonly exist in complex samples at ultralow concentrations. In this study, we fabricated novel furry amino magnetic poly-L-ornithine (PLO)/amine-poly(ethylene glycol) (PEG)-COOH/vancomycin (VCM) (AM-PPV) nanospheres with high-loading VCM for vehicle tracking and the highly efficient capture of pathogens. The magnetic core was coated with organosilica and functionalized with cilia. The core consisted of PEG/PLO loaded with VCM conjugated to Gram-positive bacterial cell membranes, forming hydrogen bonds with terminal peptides. The characterization of AM-PPV nanospheres revealed an average particle size of 56 nm. The field-emission scanning electron microscopy (FE-SEM) micrographs showed well-controlled spherical AM-PPV nanospheres with an average size of 56 nm. The nanospheres were relatively rough and contained an additional 12.4 nm hydrodynamic layer of PLO/PEG/VCM, which provided additional stability in the suspension. The furry AM-PPV nanospheres exhibited a significant capture efficiency (>90%) and a high selectivity for detecting Bacillus cereus (employed as a model for Gram-positive bacteria) within 15 min, even in the presence of other biocompatible pathogens. Moreover, AM-PPV nanospheres rapidly and accurately detected B. cereus at levels less than 10 CFU/mL. The furry nano-design can potentially satisfy the increasing demand for the rapid and sensitive detection of pathogens in clinical and environmental samples.
Keywords: bacterial pollution; detection; magnetic nanospheres; vancomycin.