Keywords

magnetic nanoparticles with Zn–DPA, broad-spectrum bacterial capture, diagnostic applications

Abstract

Bacterial infections continue to drive the need for more effective and rapid methods for bacterial analysis. To address this, magnetic nanoparticles (MNPs) have emerged as promising tools, especially when their surfaces are modified with bacteria binders. The bis-zinc–dipicolylamine (Zn–DPA) complex is known for its broad affinity to bacteria. We have synthesized MNPs via a thermal decomposition method, encapsulated them in silica, modified their surface with Zn–DPA, and tested their ability to remove bacteria. The MNPs retain their superparamagnetic properties and crystallite structure after being encapsulated. The MNPs coated with silica and Zn–DPA effectively bind and remove both Gram-positive and Gram-negative bacteria from bacterial suspensions in both PBS buffer and red blood cell suspension. The capture efficiency (CE) of bacteria is high, >0.95 for both concentrated (1 × 108 CFU) and dilute (1 × 103 CFU) suspensions of Gram-positive and Gram-negative bacteria in PBS. The bacterial capture efficiency in red blood cell suspension with 50% hematocrit ranges is high (CE > 0.95) for both concentrated and dilute suspensions of S. aureus but lower for concentrated (CE = 0.30) and dilute (CE = 0.15) suspensions of E. coli. The Zn–DPA coated MNPs have promising binding efficiencies for a broad-spectrum of bacteria within a short period of time, potentially leading to applications in diagnostic devices for both medical and industrial uses.

Original Publication Citation

Okonkwo, T. P., Gautam, R. P., Limburg, J. B., Forstrom, B. L., Houser, B. J., Rappleyea, A., ... & Harrison, R. G. (2025). Magnetic nanoparticles tethered with Zn-DPA for the removal of bacteria from red blood cell suspension. RSC advances, 15(38), 31402-31415.

Document Type

Peer-Reviewed Article

Publication Date

2025-09-02

Publisher

Royal Society of Chemistry

Language

English

College

Ira A. Fulton College of Engineering

Department

Chemical Engineering

University Standing at Time of Publication

Full Professor

Download

Share

COinS