Mesoporous silica nanoparticles capped with graphene quantum dots as multifunctional drug carriers for photo-thermal and redox-responsive release

A novel photo-thermal and redox-responsive drug delivery carrier was developed by capping mesoporous silica nanoparticles (MSNs) with graphene quantum dots (GQDs). The disulfide bonds were introduced by amidation reaction between cystine and amino functionalized MSNs. Rhodamine B (RhB), a red fluorescent dye, was loaded into the mesopores of MSNs as the model drug and GQDs capped on MSNs as gatekeepers could prevent the release of RhB. Transmission electron microscopy (TEM), nitrogen adsorption and desorption analysis, X-ray diffraction (XRD), thermogravimetric (TG) analysis and Fourier transform infrared spectroscopy (FTIR) proved that the nanocomposites MSNs capped with GODs were achieved successfully. The nanocomposites with the size of about 100 nm have excellent photo-thermal property originated from GQDs. Moreover, the nanocomposites were endowed with remarkable redox-responsion to glutathione (GSH) from disulfide bonds, and hence the loaded drugs could release controlably. In this work, we provided an exploration of photo-thermal and redox-responsive drug delivery system and the results proved that this drug delivery system can be considered as a promising candidate for drug delivery and stimuli-responsive release.