NANOSHELLS Meaning and
Definition
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Nanoshells refer to a type of nanostructured material that consists of a core-shell structure with nanometer dimensions. These nanoscale shells are typically composed of metallic materials, such as gold or silver, and possess unique optical properties as a result of their size, shape, and composition.
Traditionally, nanoshells are synthesized through a process known as colloidal chemistry. This method involves the reduction of metal ions to form spherical cores, which are subsequently coated with a thin layer of another metal. The thickness of the shell can be precisely controlled, allowing researchers to tune the properties of the nanoshells for various applications.
The unique feature of nanoshells is their ability to strongly interact with light at specific wavelengths due to the phenomenon known as surface plasmon resonance. This resonance occurs when the collective oscillation of conduction electrons in the metal shell is excited by incident electromagnetic radiation. As a result, nanoshells can absorb, scatter, or reflect light in a manner highly dependent on their size, shape, and the surrounding medium.
Owing to these distinct optical properties, nanoshells find a wide range of applications in various fields. They are extensively utilized in biomedical sensing and imaging applications, such as cancer diagnostics and therapy. The ability to selectively absorb light enables targeted thermal ablation of cancer cells when combined with near-infrared laser irradiation. Moreover, nanoshells are employed in chemical sensing, catalysis, and photovoltaics due to their tunable plasmonic resonance properties.
In summary, nanoshells are core-shell nanoparticles constructed from metallic materials with unique optical properties resulting from their size and composition. They have found significant use in various fields, ranging from biomedical applications to energy and environmental systems.
Etymology of NANOSHELLS
The word "nanoshells" is a compound word consisting of two parts: "nano" and "shells".
The prefix "nano-" comes from the Greek word "nanos", meaning "dwarf" or "very small". In scientific terminology, "nano-" is used as a prefix to indicate a factor of one billionth (10^-9). It is commonly associated with fields involving extremely small structures, such as nanotechnology.
The term "shells" refers to hollow spherical or shell-like structures. In the context of nanoshells, it refers to microscopic spherical particles with a hollow interior. These particles are often created using nanotechnology techniques.
Therefore, "nanoshells" refers to extremely small spherical or shell-like nanoparticles manufactured using nanotechnology.
