Patent ID: 8765862

Claim:
A metal nanoparticle composite, comprising: a matrix resin layer and metal nanoparticles immobilized on the matrix resin layer, the metal nanoparticles are formed by metals selected from the group consist of gold (Au), silver (Ag), copper (Cu), palladium (Pd), platinum (Pt), tin (Sn), rhodium (Rh), and iridium (Ir) and the metal nanoparticle composite comprising following structures a to e: a) the metal nanoparticles obtained through heat-reducing metal ions or metal salts contained in the matrix resin layer or a precursor resin layer thereof; b) the metal nanoparticles being present within a range from a surface of the matrix resin layer to a depth of at least 50 nm; c) particle diameters (D) of the metal nanoparticles in a range of 1 nm to 100 nm with a mean particle diameter of greater than and equal to 3 nm; and d) a spacing between adjacent metal nanoparticles is greater than and equal to the particle diameter of a larger one of the adjacent metal nanoparticles; e) the metal nanoparticles interact with light of a wavelength greater than and equal to 380 nm, for generating a local surface plasmon resonance.