Patent ID: 7923072

Claim:
A method of forming discrete regular-shaped three-dimensional silver crystals comprising the sequential steps of: establishing a plurality of nanoparticles, further comprising the steps of providing a substrate; mixing a predetermined amount of Tollen's reagent having an original Ag + concentration of 5% with a first reduction agent at a first time point forming a complex at room temperature; placing the complex on the substrate at room temperature; forming discrete three dimensional crystals, further comprising; contacting the complex with the second reduction agent at about 1 minute after the complex is placed on the substrate at room temperature by gradually adding a separate amount of a second reduction agent to the complex at a second timepoint after formation of the complex wherein the final mole ratio of reducing agent to Ag + is about 1:4; and heating the substrate between room temperature and a maximum of about 40° C. for between about 5 and 30 minutes without agitation to form discrete three-dimensional crystals between 50 nm and 5 μm in size.