Natural biopolymers: novel templates for the synthesis of nanostructures.

Biological systems such as proteins, viruses, and DNA have been most often reported to be used as templates for the synthesis of functional nanomaterials, but the properties of widely available biopolymers, such as cellulose, have been much less exploited for this purpose. Here, we report for the first time that cellulose nanocrystals (CNC) have the capacity to assist in the synthesis of metallic nanoparticle chains. A cationic surfactant, cetyltrimethylammonium bromide (CTAB), was critical to nanoparticle stabilization and CNC surface modification. Silver, gold, copper, and platinum nanoparticles were synthesized on CNCs, and the nanoparticle density and particle size were controlled by varying the concentration of CTAB, the pH of the salt solution, and the reduction time.