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Detection of pathogenic bacteria by polymerase chain reaction (PCR) is progressively emerging, although it is still hindered by a complex matrix, long-term bacterial enrichment and low bacterial abundance. Here, we report a novel material based on boronate affinity for recognition and enrichment of bacteria using a pre-PCR method. After optimization, the material exhibited high boronate affinity toward bacteria, with adsorption capacities of S. aureus and Salmonella spp. incubated in 0.01 M PBS (pH 7.4) at 37 °C for 15 min calculated as (906.60 ± 15.73) × 107 cfu/g and (582.59 ± 13.19) × 107 cfu/g, respectively, without any bacterial death during the binding process. The material was then applied to enrich S. aureus and Salmonella spp. from the spiked water and 25% cow milk samples followed by mPCR, which resulted in high bacterial enrichment and demonstrated great potential for selective enrichment of bacteria in food samples.

Rapid detection of pathogenic bacteria particularly in food samples demands efficient separation and enrichment strategies. Here, hydrophilic temperature-responsive boronate affinity magnetic nanocomposites were established for selective enrichment of bacteria. The thermo-responsive polymer brushes were developed by surface-initiated atom transfer radical polymerization of N-isopropylacrylamide (NIPAm) and allyl glycidyl ether (AGE), followed by a reaction of epoxy groups, and incorporation of fluorophenylboronic acid. The physical and chemical characteristics of the magnetic nanocomposites were analyzed systematically. After optimization, S. aureus and Salmonella spp. showed high binding capacities of 32.14 × 106 CFU/mg and 50.98 × 106 CFU/mg in 0.01 M PBS (pH 7.4) without bacteria death. Bacterial bindings can be controlled by altering temperature and the application of competing monosaccharides. The nanocomposite was then utilized to enrich S. aureus and Salmonella spp. from the spiked tap water, 25% milk, and turbot extraction samples followed by multiplex polymerase chain reaction (mPCR), which resulted in high bacteria enrichment, and demonstrated great potential in separation of bacteria from food samples.