Enhanced synergistic tumor phototherapy based on engineered MXene/AgInS₂ quantum dot heterostructures

The development of nanomaterial-based synergistic phototherapeutic platforms represents a promising strategy for efficient cancer treatment. Herein, we report the rational design and fabrication of a novel heterostructure by integrating AgInS₂ quantum dots (AIS QDs) with monolayer Ti₃C₂Tₓ MXene nanosheets (denoted as AIS + MX) via a facile thiol-metal coordination strategy. This composite nanomaterial synergistically combines the exceptional fluorescence properties and reactive oxygen species (ROS) generation capability of AIS QDs with the outstanding photothermal conversion efficiency and large specific surface area of MXene. Comprehensive characterization, including electron microscopy, spectroscopic analysis, and zeta potential measurements, confirmed the successful formation of the heterostructure. The AIS + MX composite demonstrated a remarkable photothermal conversion efficiency under 808 nm laser irradiation (0.6 W/cm² for 10 min), with a temperature increase capable of reaching 56 °C at a concentration of 100 μg/mL. Furthermore, it exhibited significantly enhanced singlet oxygen (¹O₂) generation compared to its individual components, as verified by SOSG assays. In vitro studies revealed excellent biocompatibility of AIS + MX in the dark. Upon near-infrared (NIR) light irradiation, it achieved a superior synergistic photothermal/photodynamic effect, resulting in over 95% ablation of HeLa cells. This work highlights the great potential of MXene-based heterostructures as a powerful and versatile platform for synergistic cancer phototherapy.