Fe3O4@PDA@PEI Core-Shell Microspheres as a Novel Magnetic Sorbent for the Rapid and Broad-Spectrum Separation of Bacteria in Liquid Phase

Abstract

Bacterial infection is a significant cause of morbidity and mortality to humans worldwide. Thus, a method for nonspecific, sensitive, and rapid enrichment of such bacteria is essential for bacteria detection and treatment. This study demonstrates a self-made core-shell Fe3O4@Polydopamine@Polyethyleneimine magnetic beads (Fe3O4@PDA@PEI MBs) with a high density positive charge-based magnetic separation scheme for the broad-spectrum rapid enrichment of microorganisms in the liquid phase. MBs with a high-density positive charge have a strong electrostatic attraction to most microorganisms in nature. Our scheme is as follows: (1) wrapping dopamine (DA) on the iron oxide through self-polymerization and wrapping PEI on the outermost shell layer in a mode of crosslinking with the PDA; (2) subsequently, the Fe3O4@PDA@PEI MBs were used to concentrate microorganisms from the sample solution; (3) performing magnetic separation and calculating the adsorption efficiency. The as-prepared Fe3O4@PDA@PEI MBs composite was carefully characterized by zeta potential analysis, Value stream-mapping (VSM), transmission electron microscopy (TEM), and Fourier transforms infrared spectrometry (FT-IR). In this study, both gram-positive and gram-negative bacteria could be captured in three minutes through electrostatic interaction. Furthermore, the adsorption efficiency on gram-negative (>98%) is higher than that on gram-positive (>95%), allowing for a simple, rapid assay to enrich organisms in resource-limited settings.

Modifying Superparamagnetic Iron Oxide Nanoparticles as Methylene Blue Adsorbents: A Review

“…Other materials bonding to the SPION may also be verified using FTIR techniques (Fourier transform infrared spectroscopy) [32]. The Fe-O-Fe band, which corresponds to When coating SPION with CS, PNIPAM, PEI, or PAA, SPION's surface charge can be positive, which increases the dispersibility, stability, and hydrophobicity [171][172][173][174][175][176][177][178][179]. Moreover, to produce small nanoparticles, using complexing agents such as dextran, starch, PVA, or carboxydextran during the synthesis of SPION can inhibit the nucleation growth process [38,43,180].…”

Efficient Hapten-Specific Biopanning Strategy Based on the Fe3O4@ENR-Functionalized Core–Shell Magnetic Nanoparticles

“…MNPs have the advantages of small particle size, large specific surface area, and well-liquid phase dispersion, so the MNPs can significantly increase the density of functional groups modified on their surface, thus bringing more functional properties than ordinary materials. 22 The size distribution and normal distribution fitting curve for the hydrodynamic diameter of Fe 3 O 4 MNPs are shown in Figure 2a. After calculating, the mean hydrodynamic diameter with the standard deviation of MNPs was 396.1 ± 76.1 nm.…”

“…In Liu’s research, FMNPs with amino acid using ultrasonic, long-time mixing, and “one-step” approaches were constructed to be utilized for oleaginous microalgae harvesting . In Zhang’s research, FMNPs with polydopamine and polyethylenimine were used for the broad-spectrum rapid enrichment of microorganisms in the liquid phase . Due to their small particle sizes, large specific surface area, and many other characteristics, FMNPs are especially suitable for the separation of small molecular targets in complex systems, showing advantages such as high efficiency, high specificity, and high sensitivity. − So, FMNPs are considered suitable for application in the biopanning of phages specific to haptens.…”

Ultrastable Aluminum Nanoparticles with Enhanced Combustion Performance Enabled by a Polydopamine/Polyethyleneimine Nanocoating

“…Co-deposition of PDA with polyethyleneimine (PEI) has been raised to realize fabrication of coatings with improved morphology uniformity, surface hydrophilicity, and chemical stability. − Here, we report preparation of ultrastable Al NPs with enhanced combustion performance enabled by the PDA/PEI nanocoating for the first time. Different from conventional approaches, the Al@PDA/PEI NPs were fabricated by one-step graft copolymerization of dopamine hydrochloride and PEI on the surface of Al NPs at room temperature in a very short time of 2 h. The PDA/PEI nanocoating was merely ∼15 nm in thickness and ∼0.24 wt % in mass.…”