PREPARATION AND CHARACTERIZATION OF CHITOSAN-GOLD NANOCOMPOSITES FOR DRUG DELIVERY APPLICATION

Chitosan-gold nanocomposites were fabricated via a seed-mediated goldshell growth over chitosan-gold nanocomplex and examined as a potential biomedical agent for drug delivery. Chitosan-gold nanocomplex was formed by the electrostatic interaction between of cationic chitosan nanoparticles (ca. 50 nm) and anionic gold colloids (ca. 1-3 nm) and the subsequent reduction of gold salts was conducted to form the gold clusters over the chitosan nanoparticles in the presence of reducing ascorbic acid. The resultant nanocomposites (or nanoshells) exhibited the absorption peak around 580 nm that was clearly red-shifted by ca. 60 nm as compared to gold nanoparticles. Surface morphology and plasmonic properties of chitosan-gold nanocomposites were characterized by transmission electron microscopy, field emission scanning electron microscopy (including EDX), ultraviolet-visible spectroscopy, and zeta-potential meter.