Highly fluorescent and morphology-controllable graphene quantum dots-chitosan hybrid xerogels for in vivo imaging and pH-sensitive drug carrier

Highly fluorescent graphene quantum dots (GQDs)-chitosan (CS) hybrid xerogels (GQDs-CS) were facilely synthesized, and the morphology of GQDs-CS was controllable by varying the content of GQDs in the xerogel. The GQDs-CS exhibited a porous and three-dimensional (3D) network structure when the content of GQDs reached 43% (wt%) in the xerogel, which was beneficial for drug loading and sustained release. The as-prepared GQDs-CS could also be applied for in vivo imaging since it showed strong blue, green and red luminescence under excitation of varying wavelengths. Moreover, the pH-induced protonation/deprotonation of the –NH2 groups on CS chains can result in a pH-dependent drug delivery behavior of the GQDs-CS hybrid xerogel. Highly fluorescent and morphology-controllable graphene quantum dots-chitosan hybrid xerogels for in vivo imaging and pH-sensitive drug carrier. [Display omitted] •Highly fluorescent GQDs-CS hybrid xerogels were facilely synthesized.•The as-made xerogels exhibited various morphologies with different GQDs contents.•The GQDs-CS exhibited a porous and 3D network when the content of GQDs reached 43%.•The GQDs-CS could be applied for in vivo imaging since it showed strong luminescence.•The protonation/deprotonation of –NH2 on CS result in a pH-dependent drug delivery.