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Published on: June 16, 2020
Bacteria capture with magnetic nanoparticles modified with cationic carbosilane dendritic systems
Sara Quintana-Sánchez1, Andrea Barrios-Gumiel1, Javier Sánchez-Nieves1
1Dpto. de Química Orgánica y Química Inorgánica, Universidad de Alcalá (UAH); Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá (UAH); Alcalá de Henares (Madrid), Spain; Networking Research Center for Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain; Instituto Ramón y Cajal de Investigación Sanitaria, IRYCIS, Madrid, Spain.
Magnetic nanoparticles coated with cationic carbosilane dendrons efficiently remove over 90% of S. aureus and E. coli bacteria from water using an external magnetic field. This offers a promising method for water purification.
Area of Science:
- Materials Science
- Environmental Science
- Nanotechnology
Background:
- Effective bacteria elimination from water is crucial for producing potable water.
- Polycationic macromolecules demonstrate bactericidal properties through membrane interactions.
- Developing systems for bacteria interaction and removal from water is an active research area.
Purpose of the Study:
- To functionalize iron oxide magnetic nanoparticles (MNPs) with cationic carbosilane (CBS) dendrons and dendrimers.
- To investigate the bacteria removal efficiency of these modified MNPs from water.
- To explore the influence of dendritic structure and cationic density on bacteria interaction.
Main Methods:
- Grafting CBS dendrons and dendrimers onto ~10 nm iron oxide MNPs.
- Characterization using TEM, TGA, FTIR, Z potential, and DLS.
- Assessing bacteria capture efficiency using UV, TEM, and SEM, with varying MNP concentrations.
Main Results:
- MNPs functionalized with dendrons captured over 90% of both S. aureus and E. coli at >500 ppm.
- MNPs functionalized with dendrimers primarily captured S. aureus (>90%) but not E. coli.
- Bacteria interaction sensitivity varied: Gram-positive bacteria responded to dendritic size, Gram-negative to cationic density.
Conclusions:
- Cationic carbosilane dendron-grafted MNPs are highly effective for removing both Gram-positive and Gram-negative bacteria from water.
- The size of the dendritic system and density of cationic groups are critical factors influencing bacteria capture efficiency.
- Recyclability of the modified MNPs was also explored, indicating potential for sustainable water treatment applications.
