A synergistically enhanced photothermal transition effect from mesoporous silica nanoparticles with gold nanorods wrapped in reduced graphene oxide

In this work, near-infrared (NIR)-responsive core–shell gold nanorods/mesoporous silica/reduced graphene oxide (Au/SiO₂/rGO) nanoparticles with synergistically enhanced photothermal stability and transition effect had been prepared via electrostatic interaction. Gold nanorods (AuNRs) and rGO were employed as the NIR-responsive components. UV–Vis–NIR extinction spectra revealed that the surface plasmon resonance peak of AuNRs from Au/SiO₂/rGO nanohybrids remained unchanged after 9 h NIR exposure. UV–Vis–NIR extinction results also showed that thin silica shell was superior to the thick ones in the photothermal stability improvement of Au/SiO₂/rGO nanoparticles. Moreover, the doxorubicin release of Au/SiO₂/rGO was more rapid than that of Au/SiO₂ upon NIR irradiation, indicating that synergistically enhanced photothermal effect between rGO and AuNRs endowed Au/SiO₂/rGO nanoparticles with excellent photothermal transition efficiency. Such novel NIR-responsive core–shell hybrid nanoparticles with enhanced photothermal stability and transition effect are well suited for further biological applications, such as photothermal therapy, bioimaging and drug delivery.