Targeted multifunctional nano-engineered carbon dots with enhanced synergistic photothermal/photodynamic performance for precision tumor therapy.

In this study, a novel multifunction Ce-doped carbon dots (CDs) system conjugated with arginine-glycine-aspartic acid (RGD) peptide (RGD-Ce/CDs) was successfully synthesized to enhance tumor-targeting capabilities. Structural characterization revealed uniform, ultra-small particle sizes (∼4.75 nm) and excellent dispersibility. The RGD-Ce/CDs exhibited strong absorption in both the near-infrared region (NIR-I and NIR-II) regions, achieving high photothermal conversion efficiency (PCE) of 31.8 % at 808 nm and 20.6 % at 1060 nm. Furthermore, Ce doping significantly facilitated reactive oxygen species (ROS) generation under NIR irradiation, leveraging the up-conversion effect of Ce. These properties render RGD-Ce/CDs highly promising for combined photothermal (PTT) and photodynamic therapy (PDT). Notably, RGD-Ce/CDs demonstrated excellent biocompatibility, low cytotoxicity, and remarkable photothermal stability. In vivo experiments on tumor-bearing mice showed that RGD-Ce/CDs significantly inhibited tumor growth under both 808 nm and 1060 nm laser irradiation, achieving near-complete tumors ablation in the treatment group. Importantly, RGD peptide conjugation enabled selective tumor targeting, minimizing off-target effects on healthy tissues while enhancing therapeutic efficacy. This facile synthetic strategy provides a promising platform for developing multifunctional, tumor-targeted phototherapeutic agents that synergistically integrate PTT and PDT for cancer treatment.