State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China.
Adv Healthc Mater. 2023 Dec;12(32):e2302089. doi: 10.1002/adhm.202302089. Epub 2023 Oct 26.
Self-luminous probes with near-infrared (NIR) emission are powerful tools for deep-penetration and autofluorescence-free imaging, owing to the joint optimization of both excitation and emission. However, the limited emission wavelength and requirement for multistep energy transfer limit its potency. In this study, the concept of direct wavelength conversion is established from visible light (vis) to NIR-IIb using an exquisitely designed sensitizer-activator ion pair. The manipulation of the doping hosts enables a pair of energy levels between the sensitizer and activator. Based on this a class of broadband vis-responsive nanocrystals with intense NIR-II emission is prepared. The stability and quantum yield (up to 7.4%) of the nanocrystals are further enhanced by ZnS passivation via coherent epitaxial growth. By coupling luciferase, the self-luminous probe can convert bioluminescence to NIR-IIb luminescence (>1500 nm) through a one-step energy transfer. A maximum penetrable thickness of 6 mm is achieved in the porcine tissue model. Collectively, the distinctive photon-conversion performance of this probe offers the prospect of high-resolution labeling of deep-seated lesions.
自发光探针具有近红外（NIR）发射，由于激发和发射的联合优化，是用于深穿透和无自发荧光成像的有力工具。然而，有限的发射波长和多步能量转移的要求限制了其功效。在这项研究中，使用精心设计的敏化剂-激活剂离子对，从可见光（vis）到 NIR-IIb 建立了直接波长转换的概念。掺杂主体的操纵实现了敏化剂和激活剂之间的一对能级。基于此，制备了一类具有强 NIR-II 发射的宽带 vis 响应纳米晶体。通过相干外延生长的 ZnS 钝化进一步增强了纳米晶体的稳定性和量子产率（高达 7.4%）。通过耦合荧光素酶，自发光探针可以通过一步能量转移将生物发光转换为 NIR-IIb 发光（>1500nm）。在猪组织模型中实现了最大可穿透厚度为 6mm。总的来说，该探针独特的光子转换性能为深部病变的高分辨率标记提供了前景。
