近红外Ⅱ（NIR-II）荧光成像在1000-1700纳米范围内具有很大的体内成像和治疗监测前景。目前，没有多少具备治疗诊断特性的NIR-II探针被研发出来，特别是高性能有机治疗诊断材料仍然未被充分开发利用。在此，我们展示了一种硒（Se）尾修饰方法，用于开发体内癌症光热治疗诊断引导的高效NIR-II成像材料。通过Se尾修饰策略，共轭寡聚体TPSe基纳米颗粒（TPSe NPs）实现了高亮度的NIR-II发射，最高达到1400纳米，并呈现出相对较高的60%光热转换效率与良好的稳定性。此外，TPSe NPs在NIR-II成像的指导下展示了对体外癌细胞和体内肿瘤的光热消融作用。值得注意的是，TPSe NPs具有良好的生物相容性，没有明显的副作用。因此，本研究为NIR-II治疗诊断剂的开发提供了新的见解。© 2023年BioMed Central有限公司，施普林格自然出版集团的一部分。

Second near-infrared (NIR-II) fluorescence imaging in the range of 1000-1700 nm has great prospects for in vivo imaging and theranostics monitoring. At present, few NIR-II probes with theranostics properties have been developed, especially the high-performance organic theranostics material remains underexploited. Herein, we demonstrate a selenium (Se)-tailoring method to develop high-efficient NIR-II imaging-guided material for in vivo cancer phototheranostics. Via Se-tailoring strategy, conjugated oligomer TPSe-based nanoparticles (TPSe NPs) achieve bright NIR-II emission up to 1400 nm and exhibit a relatively high photothermal conversion efficiency of 60% with good stability. Moreover, the TPSe NPs demonstrate their photothermal ablation of cancer cells in vitro and tumor in vivo with the guidance of NIR-II imaging. It is worth noting that the TPSe NPs have good biocompatibility without obvious side effects. Thus, this work provides new insight into the development of NIR-II theranostics agents.© 2023. BioMed Central Ltd., part of Springer Nature.