APPLICATIONS OF METALS AND SEMICONDUCTORS NANOPARTICLES

Nanoparticles are materials that are considered to have the dimension ranging from 1-100nm. The word nano originates from the Greek language meaning “Darf” as the word implies it connotes very small dimension. Nanoparticles can be classified base on their origin, these materials could be engineered, incidental or natural occurring. Engineered nanoparticles are the once that are produced through a chemical or physical process, while incidental nanoparticles are exhaust from machine, vehicles, and industries, the natural occurring nanoparticles are fund existing in nature, for example, dust particles.

Based on the classification, metal nanoparticles are engineered in the laboratory through the chemical and physical process. They can be synthesized from plant extract, microorganism, etc. through the oxidation and reduction of the metal by the phytochemicals present in the plant extract.
Nanomaterials have attracted the attention of many researchers around the globe due to its unique properties like a high surface area to volume ratio; these properties provide the platform for the metals nanoparticles to be used in the field of medicine, agriculture, pharmaceuticals and engineering field.
The large surface area to volume ratio provides enlarge surfaces for chemical reactions to take place than that of its bulk counterpart, therefore, promoting catalytic action due to it ability to adsorb, bind and carry other compounds like DNA, drugs, protein etc.
AGRICULTURE: Nanoparticle as served as a vehicle for nutrient transfer in plant e.g. in the form of fertilizer and foliar transfer. They can also be used for the protection of plant from diseases pathogens. Targeted application of fertilizers to plants for readily adsorption from the roots to the leaves and shoots can be successful through the nanoparticles. For instance, copper and gold nanoparticles are applied to the leaves (as foliar spray) they are basically translocated to the root from the leaves thereby activating the enzymes present to enhances defense reaction against soil borne pathogens.Although the use of nanoparticles in plant growth, protection and nutrients have some potential ecological and health effect, studies have not been conclusive. This is due to the difference the bulk materials have compared to the nanoparticles even though they are of the same element. This is illustrated on the interaction of the nanoparticles with a photon (light) and living tissues.
MEDICINE: Metal nanoparticles are used in the treatment of cancer. Cancer is a disease caused as the result of the complex mixture of genes and the environmental factors, due to the inability of the anti-cancer drug to reach the target site in sufficient amount and on the right timing without causing irreversible injury to the tissues. The nanoparticles aid in drug delivery without causing an adverse effect on the health of the cells.
Tumor Targeting: The nanoparticles are functionalized with biological moieties like monoclonal antibodies, which can exact direct anti-tumor action on the specific cell surface proton or receptors on the cancer cell leading to the deaths of the tumor cell, with little collateral damage to the neighboring cells.
Hyperthermia: Temperature difference is used in this technique, studies shows that at 50^oC the tumor cells die due to insufficient blood compared to the healthy tissue, therefore the use of temperature vector like gold nanoparticles can affect the area it was introduce, this is achieved by the magnetic delivery system or local injection into the desired site to heat up the cancerous cell beyond tolerance limit which will result in their deaths selectively.
Drug Delivery: Unstable drugs can be transported to the affected site in the living organism by using nanoparticles as the vector. The use of nanoparticles in drug delivery has proven even distribution and adequate evasiveness of biological barriers. Most anti-cancer drugs are unstable, have a short half-life in the bloodstream thereby small quantity of the drugs are likely to reach the targeted site.