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Scientists are keen to exploit the advantages that plasmonic nanoparticles can offer. Recent research using these nanoparticles has revealed many beneficial and potential applications including cancer treatment, plasmonic solar cells and biomedical applications.
Plasmonic nanoparticle research refers to the production and optical characterization of noble metal nanoparticles that differ in structure, shape, size and tunable plasmon resonance over visible-near-infrared spectral band.
Recent developments in the production, classification, electromagnetic simulation, and surface functionalization of plasmonic nanoparticles have opened up new possibilities for researchers.
The result from many research projects have led to several potential biomedical applications such as optically stable bio- imaging agents, biosensor devices, and therapeutic agents.
Multifunctional plasmonic nanostructures are proving to be more advantageous in bio- applications. The realization of this research has led scientists to work on combining the unique plasmonic properties with other operational qualities such as photoluminescence, dispersibility in aqueous solutions, resistance to degradation, and magnetism.
Biomedical – Plasmonic nanoparticles are photostable and thus can be used as bio-nanoprobes. Plasmonic nanoparticles scatter light vigorously, and hence can be identified easily under dark-field illumination and other sensing techniques. Thus they can be utilized in various in vitro biological applications.
Furthermore, they can be used to analyze how nanoparticles interact with cells. Gold and silver nanoparticles can be applied as plasmonic biosensors for finding specific biomolecules and proteins that are useful for specific diseases.
Plasmonic gold and silver nanoparticles have unique optical, electrical, and thermal properties and hence are used in applications such as antimicrobial coatings and molecular diagnostics.
Color engineering – The unique optical properties of metal nanoparticles are very useful in color engineering. Here customized nanoparticle formulations are created for the purpose of absorbing and scattering specific wavelengths of light to generate a color. Plasmonic nanoparticles can concurrently absorb and scatter light to offer a bichromic color result.
The rapid progress in scaled manufacturing techniques has enabled plasmonic nanoparticles with their unique optical properties to be added into plastics, cosmetics, paints, coatings and composites.
Plasmonic solar cells – Plasmonic nanoparticles possess low absorption property as well as the ability to scatter light back into a photovoltaic structure. Researchers are keen on exploiting these aspects to enhance solar cell efficiency by forcing more light to be absorbed by solar cells.
Plasmonic solar cell
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Spectroscopy – Plasmonic nanoparticles are widely used for high resolution spectroscopy. Recent research projects have used 40 nm gold nanoparticles to bind specifically to epidermal growth factor receptors (EGFRs), so as to establish the density of those receptors on a cell. Quantitative data regarding the EGFR density can be procured based on the shift in resonant frequency of the plasmonic nanoparticles.
Cancer treatment – Gold nanorods functionalized with epidermal growth factor can be used for targeted radiation treatments. Research on optical generation and detection of photo-thermal vapor bubbles around plasmonic nanoparticles led to the nanoparticles being used in a non-invasive highly sensitive imaging of target cells in leukemia and carcinoma culture and primary cancerous cells.
Others - Metal nanoparticles are being used to create simple and new structures such as thin films, colloids, wires, shells, and stars. They are also used in surface plasmon photonic devices.
With the rapid advancement in technologies, plasmonic nanoparticles are likely to find use in many more applications in the coming years.
References and Further Reading