▎ 摘　　要

In this study, a simple method was developed to synthesize the zeolitic imidazolate frameworks-8/graphene oxide (ZIF-8/GO) nanocrystals with encapsulation of drug molecules simultaneously, which possess the pH-controlled drug release and photothermal effect. The structure, drug release behavior, photothermal effect of the ZIF-8/GO nanocrystals were investigated. Using fluorescein as a model drug, the results showed that the fluorescein-ZIF-8/GO nanocrystals with a particle size of 50-100 nm were monodisperse and exhibited pH-controlled release behavior. On the other hand, using breast cancer line 4T1 cells as a cellular system, the fluorescein-ZIF-8/GO nanocrystals showed negligible cytotoxicity and could be internalized into cancer cells. More importantly, the fluorescein-ZIF-8/GO nanocrystals had excellent photothermal effect by near infrared (NIR) irradiation (lambda = 808 nm) to kill cancer cells with high efficacy. Therefore, the construction strategy to the fluorescein-ZIF-8/GO nanocrystals would be promising for the development of multifunctional platform with potential synergistic therapy. (C) 2016 Elsevier Inc. All rights reserved.