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Updated: Mar 22, 2026
Synthesis of Functionalized Magnetic Nanoparticles, Their Conjugation with the Siderophore Feroxamine and its Evaluation for Bacteria Detection
Published on: June 16, 2020
Affinity capture using peptide-functionalized magnetic nanoparticles to target Staphylococcus aureus
Fang-Yin Kuo1, Wei-Lien Lin2, Yu-Chie Chen3
1Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan. yuchie@mail.nctu.edu.tw.
Abstract:
Staphylococcus aureus, a commonly found pathogen, can cause food poisoning and infections. Thus, it is necessary to develop analytical methods for the rapid screening of S. aureus in suspicious samples. Magnetic nanoparticles (MNPs) are widely used as affinity probes to selectively enrich target species from complex samples because of their high specific surface area and magnetic properties. The MNP surface should be functionalized to have the capability to target specific species. We herein propose a straightforward method to functionalize aluminum oxide-coated iron oxide (Fe3O4@Al2O3) MNPs with the peptide HHHHHHDEEGLFVD (D). The peptide D was comprised of three domains: polyhistidine (H6) used as the linker, DEE added as the spacer, and GLFVD used for targeting S. aureus. D was immobilized on the surface of Fe3O4@Al2O3 MNPs through H6-Al chelation. Our results showed that the D-functionalized Fe3O4@Al2O3 MNPs (D-Fe3O4 MNPs) possess the capability to target S. aureus. The selective trapping experiments were conducted under microwave-heating for only 60 s, and sufficient bacterial cells were trapped by the MNPs to be identified by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). We demonstrated that the D-Fe3O4@Al2O3 MNPs combined with MALDI-MS can be used to rapidly characterize trace amounts of S. aureus in complex juice and egg samples.
Insights
Researchers developed peptide-functionalized magnetic nanoparticles (MNPs) for rapid Staphylococcus aureus detection. These D-Fe3O4 MNPs selectively capture S. aureus in 60 seconds for quick identification using MALDI-MS.
Area of Science:
- Analytical Chemistry
- Nanotechnology
- Microbiology
Background:
- Staphylococcus aureus is a common pathogen causing food poisoning and infections.
- Rapid and selective analytical methods are needed for S. aureus screening.
- Magnetic nanoparticles (MNPs) offer high surface area and magnetic properties for sample enrichment.
Purpose of the Study:
- To develop a straightforward method for functionalizing iron oxide MNPs with a peptide for S. aureus targeting.
- To evaluate the efficiency of D-functionalized Fe3O4@Al2O3 MNPs in selectively capturing S. aureus.
- To demonstrate a rapid analytical method combining functionalized MNPs and MALDI-MS for S. aureus detection.
Main Methods:
- Functionalization of aluminum oxide-coated iron oxide MNPs (Fe3O4@Al2O3) with a peptide (D) containing polyhistidine linker, DEE spacer, and GLFVD targeting domain.
- Immobilization of peptide D onto Fe3O4@Al2O3 MNPs via H6-Al chelation.
- Selective trapping of S. aureus using D-Fe3O4 MNPs under microwave heating (60 s).
- Identification of trapped S. aureus using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS).
Main Results:
- D-functionalized Fe3O4@Al2O3 MNPs (D-Fe3O4 MNPs) demonstrated the capability to target and capture S. aureus.
- Selective trapping was achieved rapidly within 60 seconds using microwave heating.
- Sufficient bacterial cells were trapped for subsequent identification by MALDI-MS.
- The method successfully characterized trace amounts of S. aureus in complex food matrices (juice and egg samples).
Conclusions:
- Peptide D functionalization enables Fe3O4@Al2O3 MNPs to selectively target S. aureus.
- The D-Fe3O4 MNPs combined with MALDI-MS provide a rapid and effective method for trace S. aureus detection.
- This approach holds promise for quick screening of S. aureus in food safety applications.
