Platinum Nanoparticles are sub-micrometre-sized particles of the metal platinum in a fluid such as water. They are found in the form of a suspension or colloid which is defined as particles that remain suspended without forming a dissolved solution. Commercially, the colloidal platinum includes products which contain different concentrations of ionic platinum compounds, platinum colloids, platinum nano-particles and ionic platinum in purified water. The platinum nano-particles range in sizes between 2-3 nanometres (nm). There are trillions of platinum nano-particles which are found suspended in the brownish red or black coloured colloidal solution. They come in lots of shapes such as cubes, spheres, and rods.
The antioxidant properties of the platinum nanoparticles are the subject of substantial research in applications encompassing nanotechnology, medicine as well as in the synthesis of novel materials with exceptional properties. These nano-particles are made-up by reduction of the hexa-chloroplatinate. Once the hexachloroplatinate is dissolved, the solution is stirred continuously and a reducing agent is added. It results in platinum ions to get reduced to neutral platinum atoms. With the formation of large number of platinum atoms, the solution becomes supersaturated and eventually started to precipitate in the form of sub-nanometre particles. The remaining platinum atoms got attached to the existing particles and in case the solution is stirred vigorously, the particles become uniform in size.
The platinum nanoparticles offer various safety issues medically as well as environmentally. The basic reason behind these issues is the high surface to volume ratio that renders the particles very reactive or catalytic. It is dangerous to inhale the platinum nanoparticles and may lead to inflammation and disease in the lungs. They can readily pass across the cell membranes in the humans and other organisms. Moreover, their interactions with biological systems are not known. The free nanoparticles get agglomerated in the environment quickly and thereby leaving the nano regime.
