Rationally Assembling Different Surface Functionalized Carbon Dots for Enhanced Near-infrared Tumor Photothermal Therapy

Carbon dots (CDs) have emerged as promising photothermal agents for near-infrared (NIR)-mediated tumor therapy due to their excellent biocompatibility and tunable optical properties. However, it is still unclear how to precisely control their assembly behavior to enhance NIR absorption and photothermal conversion efficiency. In this work, we present a hyper-assembled electron donor/acceptor CDs complex (S-d/a-CDs), constructed by integrating electron-donating CDs (d-CDs) with electron-withdrawing CDs (a-CDs). This configuration significantly enhances the NIR absorption capacity of S-d/a-CDs. Under 740 nm laser irradiation, S-d/a-CDs achieve a remarkable photothermal conversion efficiency (PTCE) of 65.8 %. S-d/a-CDs exhibit negligible cytotoxicity and effective tumor accumulation capacity through intravenous administration, enabling complete tumor elimination after NIR laser irradiation. To our knowledge, this study is the first to exploit synergistic assembles of two types of CDs for photo-physical property engineering, establishing a groundbreaking paradigm for the development of advanced NIR-triggered photothermal materials.