Enhancing the colloidal stability and surface functionality of molybdenum disulfide (MoS2) nanosheets with hyperbranched polyglycerol for photothermal therapy

Abstract

Molybdenum disulfide (MoS2) nanosheets are gaining increasing attention due to their attractive properties and myriads of potential applications. However, challenges in the enhancement of their colloidal stability and surface functionality still remain and significantly restrict their practical applications. Herein, we present a viable approach to functionalize MoS2 nanosheets with multihydroxy hyperbranched polyglycerol (HPG) shell by surface-initiated ring-opening polymerization technique. The grafting of HPG from the surface of MoS2 nanosheet yielded MoS2-g-HPG nanohybrid with excellent water dispersibility, good biocompatibility, and greatly enhanced colloidal stability against pH change, ionic strength variation and long-term storage. The MoS2-g-HPG also exhibited excellent light-to-heat conversion capability for in vitro photothermal therapy application. Meanwhile, the MoS2-g-HPG showed favorable surface functionality owing to its numerous surface hydroxyl groups, as demonstrated by the conjugation of functional molecules such as fluorescent dye rhodamine B. As such, this paper opens up new opportunities to empower MoS2 nanosheets and other two-dimensional inorganic nanosheets with desired properties for various applications.