A Visible- and NIR-Light Responsive Photothermal Therapy Agent by Chirality-Dependent MoO3-x Nanoparticles

Chirality-based semiconducting nanocrystals, as an emerging area, are envisioned to have great potential in chiral sensing, biomedicine, and chiroptical devices. Herein, chiral substoichiometric molybdenum oxide (l/d-Cys-MoO3-x) nanoparticles are synthesized via step-by-step reduction treatment with chiral cysteine molecules. The obtained nanoparticles are used as visible- and near-infrared-light dual responsive photothermal therapy agent for tumor cell ablation. Notably, the chiral nanoparticles show chiral selectivity for incident light, i.e., when irradiated by left-circularly polarized light, l-Cys-MoO3-x is the most sensitive agent giving the highest mortality for HeLa cell ablation in vitro, and vice versa for right-circularly polarized light with d-Cys-MoO3-x. In comparison to traditional photothermal therapy with near-field light source, the investigations with chiral visible light at 532 nm indicate the possibility of chiral Cys-MoO3-x nanoparticles for visible light-based phototherapy via metal-ligand charge transfer chirality, which provides insights for new methods in nanotechnology supported photothermal treatments.