Preparation of functionalized magnetic nanoparticles conjugated with feroxamine and their evaluation for pathogen detection

Abstract

This work reports the preparation of a conjugate between amino-functionalized silica magnetite and thesiderophore feroxamine. The morphology and properties of the conjugate and intermediate magneticnanoparticles (MNPs) were examined by powder X-ray diffraction (XRD), Fourier Transform Infraredspectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), magnetizationstudies, zeta potential measurements, Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray (EDX) mapping. Furthermore, this study investigated the interaction between the functionalizedmagnetic NPs andYersinia enterocoliticawild type (WC-A) using Scanning Electron Microscopy (SEM)and TEM images. In addition, the interaction between MNPs and aY. enterocoliticamutant strain lackingferoxamine receptor FoxA, was also used to study the binding specificity. The results showed that thecapture and isolation ofY. enterocoliticaby the MNPs took place in all cases. Moreover, the specificinteraction between the MNP conjugate and bacteria did not increase after blocking the free aminegroups witht-butoxycarbonyl (Boc) and carboxylic acid (COOH) functional groups. Electrostatic surfaceinteractions instead of molecular recognition between MNP conjugate and feroxamine receptor seem torule the attachment of bacteria to the conjugate