Graphitic Carbon Nitride Quantum Dots Embedded in Carbon Nanosheets for Near-Infrared Imaging-Guided Combined Photo-Chemotherapy

Abstract

Rational design of metal-free multifunctional therapeutic reagents offers great opportunities for cancer treatment in the clinic. Here, graphitic carbon nitride (g-C₃N₄) quantum dots embedded in carbon nanosheets (CNQD-CN) are <i>in situ</i> prepared <i>via</i> a one-pot hydrothermal approach with formamide as carbon and nitrogen source. The CNQD-CN not only serves as an excellent near-infrared (NIR) fluorescent marker but also acts as a pH-responsive nanocarrier. Moreover, the CNQD-CN possesses both light-to-heat conversion and singlet oxygen generation capabilities under a single NIR excitation wavelength. Further investigations show that systemic delivery of doxorubicin (DOX) using the multifunctional CNQD-CN nanocarrier under NIR irradiation was highly effective to cause cancer cell apoptosis <i>in vitro</i> and inhibit tumor growth <i>in vivo</i>. CNQD-CN represents a multifunctional therapeutic platform for synchronous cancer imaging and treatment through the synergistic effect of phototherapy and chemotherapy.