Circular Dichroism Spectroscopy as a Powerful Tool for Unraveling Assembly of Chiral Non-luminescent Aggregates of Photosensitizer Molecules on Nanoparticle Surfaces

Recent developments in nanoscience and nanotechnology significantly help improve the properties of traditional materials. A striking example of this is the formation of hybrid nanostructures based on nanoparticles and photosensitizer molecules, the potential range of applications of which extends from photovoltaics to biomedicine. However, the creation of new and effective hybrid nanomaterials of this form inevitably entails new challenges, one of which is a common and critical problem of aggregation of both nanoparticles and photosensitizer molecules. Therefore, a fundamental challenge is to determine the presence of these aggregates, which will produce a significant step toward creating a new generation of materials and devices of broad-spectrum applicability. Here we report on the key role of circular dichroism spectroscopy as a tool to detect the formation of non-luminescent aggregates of chlorin e6, a second-generation photosensitizer, in a hybrid nanostructure with ZnS:Mn quantum dots. These aggrega...