Applications Of Plasmonic Nanoparticles Research Articles

Plasmonic nanotechnology for photothermal applications - an evaluation.

The application of plasmonic nanoparticles is motivated by the phenomenon of surface plasmon resonance. Owing to the tunability of optothermal properties and enhanced stability, these nanostructures show a wide range of applications in optical sensors, steam generation, water desalination, thermal energy storage, and biomedical applications such as photothermal (PT) therapy. The PT effect, that is, the conversion of absorbed light to heat by these particles, has led to thriving research regarding the utilization of plasmonic nanoparticles for a myriad of applications. The design of conventional nanomaterials for PT conversion has focussed predominantly on the manipulation of photon absorption through bandgap engineering, doping, incorporation, and modification of suitable matrix materials. Plasmonic nanomaterials offer an alternative and attractive approach in this regard, through the flexibility in the excitation of surface plasmons. Specific advantages are the considerable improved bandwidth of the absorption, a higher efficiency of photon absorption, facile tuning, as well as flexibility in the synthesis of plasmonic nanomaterials. This review of plasmonic PT (PPT) research begins with a theoretical discussion on the plasmonic properties of nanoparticles by means of the quasi-static approximation, Mie theory, Gans theory, generic simulations on common plasmonic material morphologies, and the evaluation processes of PT performance. Further, a variety of nanomaterials and material classes that have potential for PPT conversion are elucidated, such as plasmonic metals, bimetals, and metal-metal oxide nanocomposites. A detailed investigation of the essential, but often ignored, concept of thermal, chemical, and aggregation stability of nanoparticles is another part of this review. The challenges that remain, as well as prospective directions and chemistries, regarding nanomaterials for PT conversion are pondered on in the final section of the article, taking into account the specific requirements from different applications.

Multipolar and bulk modes: fundamentals of single-particle plasmonics through the advances in electron and photon techniques

Abstract Recent developments in the application of plasmonic nanoparticles have showcased the importance of understanding in detail their plasmonic resonances at the single-particle level. These resonances can be excited and probed through various methods, which can be grouped in four categories, depending on whether excitation and detection involve electrons (electron energy loss spectroscopy), photons (e.g., dark-field microscopy), or both (cathodoluminescence and photon-induced near-field electron microscopy). While both photon-based and electron-based methods have made great strides toward deepening our understanding of known plasmonic properties and discovering new ones, they have in general progressed in parallel, without much cross-pollination. This evolution can be primarily attributed to the different theoretical approaches driving these techniques, mainly dictated by the inherent different nature of electrons and photons. The discrepancies that still exist among them have hampered the development of a holistic approach to the characterization of plasmonic materials. In this review therefore, we aim to briefly present those electron-based and photon-based methods fundamental to the study of plasmonic properties at the single-particle level, with an eye to new behaviors involving multipolar, propagating, and bulk modes coexisting in colloidal nanostructures. By exploring the key fundamental discoveries in nanoparticle plasmonics achieved with these techniques, herein we assess how integrating this information could encourage the creation of a unified understanding of the various phenomena occurring in individual nanoparticles, which would benefit the plasmonics and electron microscopy communities alike.

Plasmonic Heating of Nanostructures.

The absorption of light by plasmonic nanostructures and their associated temperature increase are exquisitely sensitive to the shape and composition of the structure and to the wavelength of light. Therefore, much effort is put into synthesizing novel nanostructures for optimized interaction with the incident light. The successful synthesis and characterization of high quality and biocompatible plasmonic colloidal nanoparticles has fostered numerous and expanding applications, especially in biomedical contexts, where such particles are highly promising for general drug delivery and for tomorrow's cancer treatment. We review the thermoplasmonic properties of the most commonly used plasmonic nanoparticles, including solid or composite metallic nanoparticles of various dimensions and geometries. Common methods for synthesizing plasmonic particles are presented with the overall goal of providing the reader with a guide for designing or choosing nanostructures with optimal thermoplasmonic properties for a given application. Finally, the biocompatibility and biological tolerance of structures are critically discussed along with novel applications of plasmonic nanoparticles in the life sciences.

Colloidal Synthesis and Applications of Plasmonic Metal Nanoparticles

Plasmonic metal nanoparticles attract intense research attention because of their fascinating surface plasmon resonance properties and their potential applications in diverse fields. Here, some of the recent research efforts on the synthesis and applications of plasmonic metal nanoparticles are highlighted. Starting from the colloidal synthesis of metal nanoparticles, various shaped silver and gold nanostructures are discussed. The applications of plasmonic nanoparticles in photocatalysis, surface-enhanced Raman spectroscopy (SERS), and devices are used as excellent examples showcasing the advantages of these nanoparticles. The report closes with a brief summary and discussion on the challenges and future direction in this research field.