Frontiers in the production and applications of metallic nanoparticles

Abstract

Nanoparticles are nano-sized particles with a diameter of 100 nm or less. Metallic nanoparticles such as gold and silver have properties different from those of the bulk. Gold nanoparticles dispersion solution with a diameter of tens nanometer has an absorption peak around 530 nm, induced by localized surface plasmon resonance. This solution shows red color, and the optical properties of gold nanoparticles are applied to the red labels for antigen tests and chemical sensors for detecting biomolecules because gold nanoparticles have a high affinity with biomolecules such as proteins, DNA, enzymes, and microorganisms. In general, biosensing such as antigen tests requires nanoparticles with strong absorption and narrow particle size distribution because the absorption peak is large, and the sharp peak increases the analysis accuracy. Based on the current status of metal nanoparticles, this paper introduces types of metallic nanoparticles, production methods, and their applications.