Silicon nanoparticles produced by femtosecond laser ablation in water as novel contamination-free photosensitizers

We report the synthesis of novel inorganic contamination-free photosensitizers based on colloidal silicon nanoparticles prepared by laser ablation in pure deionized water. We show that such nanoparticles are capable of generating singlet oxygen under laser irradiation with a yield estimated at 10 of that of photofrin, which makes them a potential candidate for therapeutics, antiseptics, or disinfectants. We also discuss a model of generation and the possibility for optimizing its release. Potential advantages of such novel inorganic photosensitizers include stable and nonphotobleaching release, easy removal, and low dark toxicity.