Gold–Nanoparticles A Novel Nano-Photosensitizer for Photodynamic Therapy

Gold Nanoparticles (GNPs) of size below 5 nm were prepared by reduction of Chloroauric acid using sodium citrate and NaBH₄ and characterized. High resolution transmission electron microscopic measurements revealed their size less than 5nm. Their photodynamic action was tested in human erythrocytes. The percent hemolysis showed a decrease in PDA above a particular GNPs concentration. The study of the effect of scavengers GSH and NaN₃ showed formation of a considerable amount of superoxide anion and singlet oxygen that caused cell death. The detailed mechanism is discussed. GNPs being nontoxic serve as proper substitute for the conventional photosensitizers such as organic dyes.