Multichannel near-infrared (NIR)-II imaging provides more precise and detailed information for studying complex biological processes. When studying specific biological processes, a separated single signal and multisignals are essential but difficult to obtain by traditional multichannel NIR-II imaging methods. Taking advantage of the unique optical properties of lanthanide ions, especially in atom-like absorbance and emission spectroscopy in the NIR region, in this study, we synthesized two lanthanide-doped nanoprobes, NaYF₄:Gd@NaYF₄:Nd@NaYF₄ (cssNd) and NaYF₄:Gd@NaYF₄:Er@NaYF₄ (cssEr). These two nanoprobes show orthogonal NIR-II emissions (1064 and 1330 nm for cssNd and 1550 nm for cssEr) under 730 and 980 nm excitation, respectively. The feasibility of cssNd and cssEr for multichannel NIR-II imaging was proven in vitro. Under different methods of administering the nanoprobes, in vivo multichannel NIR-II imaging with both the separated single signal and multisignals was successfully performed and could spatially distinguish tissues under two different excitation sources. Our results provide a new method for multichannel NIR-II imaging with separable signals, which is promising for precisely studying complex biological processes precisely.

中文翻译：

---

正交近红外II成像可实现基于镧系元素掺杂纳米探针的空间区分组织。

多通道近红外（NIR）-II成像为研究复杂的生物过程提供了更精确和详细的信息。当研究特定的生物学过程时，分离的单个信号和多个信号是必不可少的，但是很难通过传统的多通道NIR-II成像方法获得。利用镧系元素离子的独特光学性质，特别是在近红外区域的原子样吸收和发射光谱学中，在本研究中，我们合成了两种掺杂镧系元素的纳米探针NaYF ₄：Gd @ NaYF ₄：Nd @ NaYF ₄（ cssNd）和NaYF ₄：Gd @ NaYF ₄：Er @ NaYF ₄（cssEr）。这两个纳米探针分别在730和980 nm激发下显示正交的NIR-II发射（cssNd为1064和1330 nm，cssEr为1550 nm）。在体外证明了cssNd和cssEr用于多通道NIR-II成像的可行性。在不同的纳米探针给药方法下，具有分离的单个信号和多信号的体内多通道NIR-II成像已成功完成，并且可以在两个不同的激发源下在空间上区分组织。我们的结果提供了一种具有可分离信号的多通道NIR-II成像的新方法，这对于精确地研究复杂的生物过程很有希望。