The low reactive oxygen species production capability and the shallow tissue penetration of excited light (UV) are still two barriers in photodynamic therapy (PDT). Here, Au cluster anchored black anatase TiO_2−x nanotubes (abbreviated as Au₂₅/B‐TiO_2−x NTs) are synthesized by gaseous reduction of anatase TiO₂ NTs and subsequent deposition of noble metal. The Au₂₅/B‐TiO_2−x NTs with thickness of about 2 nm exhibit excellent PDT performance. The reduction process increased the density of Ti³⁺ on the surface of TiO₂, which effectively depresses the recombination of electron and hole. Furthermore, after modification of Au₂₅ nanoclusters, the PDT efficiency is further enhanced owing to the changed electrical distribution in the composite, which forms a shallow potential well on the metal–TiO₂ interface to further hamper the recombination of electron and hole. Especially, the reduction of anatase TiO₂ can expend the light response range (UV) of TiO₂ to the visible and even near infrared (NIR) light region with high tissue penetration depth. When excited by NIR light, the nanoplatform shows markedly improved therapeutic efficacy attributed to the photocatalytic synergistic effect, and promotes separation or restrained recombination of electron and hole, which is verified by experimental results in vitro and in vivo.

中文翻译：

---

Au纳米团簇敏化的黑色TiO2-x纳米管，用于近红外光驱动的增强光动力疗法

低活性氧的产生能力和激发光（UV）的浅层组织渗透仍然是光动力疗法（PDT）的两个障碍。在此，通过气态还原锐钛矿型TiO ₂ NTs并随后沉积贵金属，合成了金簇锚定的黑色锐钛矿型TiO _{2- x}纳米管（缩写为Au ₂₅ / B-TiO ₂ - _x NTs）。厚度约为2 nm的Au ₂₅ / B-TiO ₂ - _x NTs表现出优异的PDT性能。还原过程增加了TiO ₂表面上Ti ³⁺的密度，有效地抑制了电子与空穴的复合。此外，在对Au ₂₅纳米团簇进行改性之后，由于复合材料中电分布的改变，PDT效率进一步提高，从而在金属-TiO ₂界面上形成了浅势阱，从而进一步阻碍了电子与空穴的复合。特别是，锐钛矿二氧化钛的还原₂可以花费TiO 2的光响应范围（UV）₂到具有高组织穿透深度的可见光甚至近红外（NIR）光区域。当被近红外光激发时，纳米平台显示出归因于光催化协同效应的显着改善的治疗功效，并且促进了电子与空穴的分离或受阻复合，这在体外和体内实验结果中得到了证实。