An immune magnetic nano-assembly for specifically amplifying intercellular quorum sensing signals

[Display omitted] •Small immune magnetic particles with diameter of ∼12 nm were fabricated.•The specific surface area of immune magnetic particles was 96.5 m2/g.•The distribution of antibody on the surface of magnetic particles was 25.8 μg/m2.•More than 3 × 108 of E. coli cells can be collected by 1 mg magnetic particles.•The QS signal was amplified ∼3 times than nature QS signal at total cell OD 0.08. Quorum sensing (QS) enables intercellular communication after bacterial cells sense the autoinducers have reached or exceeded a critical concentration. Selectively amplifying specific bacterial “quorum” activity at a lower cell density is still a challenge. Here, we propose a novel platform of immune magnetic nano-assembly to amplify specific bacterial QS signaling via improving the bioavailability of autoinducers-2 (AI-2, furanosyl borate) from sender (wide-type, WT cells) to receiver (reporter cells). Antibody coated magnetic nanoparticle (MNPAB) was fabricated with an average diameter of 12 nm and a specific surface area of 96.5 m2/g. The distribution efficiency of the antibody on the surface was 25.8 μg/m2 of magnetic nanoparticles. It was found that more than 3 × 108 of K12 serotype Escherichia coli (E. coli) reporter or WT cells were collected using 1 mg fabricated MNPAB at a saturated condition. The MNPAB not only captured E. coli WT cells but also brought them into proximity of E. coli (CT104, pCT6+pET-DsRed) reporter cells via magnetic attraction. The amplified QS signaling of the reporter cells by this immune magnetic nano-assembly was approximately 3 times higher than the nature QS signaling in cell suspension at optical density (OD) 0.08. This study foresees potential applications in amplifying specific biological QS signals based on a preprogrammed design.