Synergetic Effect of Mo6 Clusters and Gold Nanoparticles on the Photophysical Properties of Both Components

Photodynamic and photothermal therapies (PDT, and PTT, respectively) are promising candidates for multimodal anticancer therapies (i.e., combinations of therapies), since their action is based on mechanisms that generally cannot be resisted by cancer cells, that is, generation of highly oxidizing oxygen species and high temperature, respectively. Herein, hybrid materials that combine octahedral molybdenum clusters as potential PDT agents and plasmonic spherical gold nanoparticles (AuNPs) as PTT agents are reported. Partial overlap of the photoemission spectrum of the cluster and the surface plasmon resonance band of the AuNPs facilitates energy transfer between the photoactive components, which resulted in synergetic enhancement of their photophysical properties. Specifically, by careful selection of the spacing between the cluster and the gold nanoparticle, a significant increase in luminescence and photosensitizing properties of the cluster was achieved in comparison with similar, but gold-free, particles. On the other hand, the cluster complex facilitated energy conversion to heat by gold particles and hence increased the heating rate under laser irradiation.

Automated summary

Photodynamic and photothermal therapies are promising candidates for multimodal anticancer therapies, and combining octahedral molybdenum clusters with plasmonic spherical gold nanoparticles can enhance their photophysical properties synergistically. By careful selection of spacing between the cluster and the gold nanoparticle, significant improvements in luminescence and photosensitizing properties of the cluster were achieved compared to similar gold-free particles. The cluster complex also facilitated energy conversion to heat by gold particles, increasing the heating rate under laser irradiation.