PEGylated graphene oxide-capped gold nanorods/silica nanoparticles as multifunctional drug delivery platform with enhanced near-infrared responsiveness.

In this paper, near infrared (NIR)-responsive core-shell gold nanorods/mesoporous silica nanoparticles capped with PEGylated graphene oxide (GNRs/SiO2/GO-PEG) were prepared via electrostatic and physical absorption interactions. Hybrid nanoparticles display distinct photothermal stability in physiological environment and acidic media because of the introduction of biocompatible GO-PEG. In addition, due to the high specific surface area of GO-PEG and synergistically enhanced photothermal effect between GO-PEG and GNRs, GNRs/SiO2/GO-PEG nanoparticles exhibit excellent drug loading efficiency and superior photothermal conversion efficiency (39.53%). More importantly, significant pH-/NIR- dual responsive drug release upon NIR irradiation could be observed from GNRs/SiO2/GO-PEG nanoparticles due to the π-π cooperative interaction between GO-PEG and doxorubicin hydrochloride (DOX), and synergistically enhanced NIR-responsiveness derived from GNRs/GO-PEG. The present paper furnishes a green and feasible method to prepare smart core/shell hybrid nanoparticles with high drug loading efficiency and excellent photothermal conversion efficiency, which possess great perspectives as a multifunctional platform for remotely controllable drug delivery.