A new approach for the fabrication copper nanoparticles by a wet chemical reduction method is reported. The natural resources arginine as amino compound and several monosaccharides (xylose, ribose, galactose and glucose) react characteristically performing an Amadori rearrangement followed by a Maillard type reaction. This reaction carried out in an aqueous solution ensures an environmentally friendly way of reducing copper(II) ions leading to the formation of the desired nanoparticles. By changing the concentration of the amino acid, simultaneously acting as a complexing agent, it is possible to tune the size of the resulting nano particles to a certain degree down to 3 nm. This nontoxic and facile preparation route with quantitative yield opens a wide field of applications ranging from electronics to medical approaches.