Structure and in-cellulo stability of NIR-emitting Ag2S-based quantum dots

Silver sulphide (Ag2S) quantum dots (QDs) are semi-conducting nanocrystals with optical properties of great interest for biological applications including a broad absorbance spectrum and tune-able NIR emission that falls within the biological transparency window. However, prior to any in-vivo or clinical applications, their stability in biological systems and biocompatibility must be fully investigated. We have developed a panel of Ag2S with differing sizes and optimised optical properties. Via XAFS, we intend to study the local structure of silver in these QDs in both aqueous media and cellular models, including 3D cell cultures that mimic the liver. This information in conjunction with the photo-physical characterisation and cytotoxicity assays will help us not only understand the effects of the reaction conditions on the structure and optical properties but enable us to propose the best formulations for the further development of nano-platforms for theranostic applications.