Magnetic nanoparticles are tiny particles that can be controlled by magnets. They are useful in many areas, but they have a big problem. When scientists try to modify them, they often clump together and become unstable. This makes them hard to use.

To fix this, a simple method was created. It uses a technique called layer-by-layer coating. This involves wrapping the nanoparticles in layers of special materials. Two of these materials are polyallylamine hydrochloride and poly(styrene sulfonic acid) sodium salt. This coating keeps the nanoparticles from clumping and makes them more useful.

The method allows scientists to attach different molecules to the nanoparticles. These molecules can be redox probes, which are useful in electrochemical sensors. Examples include ferrocene, anthraquinone, or monocarboxymethylene blue. The method also allows for the attachment of bio-probes, like IgG, which are important in biological studies.

The nanoparticles are first functionalized with the redox molecules in organic solvents. Then, they are protected by the layer-by-layer coating. This protection is important when the nanoparticles are put into solutions with high ionic strength, like phosphate-buffered saline. The outer layer of the coating allows biomolecules to attach to the nanoparticle surface without needing chemical cross-linking.

The size of the coated nanoparticles was measured using transmission electron microscopy. The sizes were found to be around 11. 0 nanometers for those with ferrocene, 10. 5 nanometers for those with anthraquinone, and 12. 4 nanometers for those with monocarboxymethylene blue. The redox properties of these nanoparticles were also studied using square wave voltammetry. The redox intensities were measured as 0. 64 microamperes for ferrocene, 23. 25 microamperes for anthraquinone, and 0. 48 microamperes for monocarboxymethylene blue.

The method showed that the nanoparticles can effectively bind to IgG. The binding efficiency was up to 78%, as shown by SDS-PAGE gel analysis. This method is versatile and effective for functionalizing magnetic nanoparticles. It combines redox and biological properties, making them useful for disease diagnosis and point-of-care testing.

The layer-by-layer coating method is a big step forward. It solves the problem of nanoparticle aggregation and instability. This makes magnetic nanoparticles more useful in many applications. However, more research is needed to fully understand the potential of this method. Scientists need to explore how well these nanoparticles work in real-world conditions. They also need to study the long-term effects of using these coated nanoparticles in biological systems.

Smarter Magnetic Particles for Better Health Tools

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