AI 中文总结
研究镧系掺杂上转换粒子在生物成像中的应用难题，通过应用于铋掺杂UCPs的方案，利用其量子产率优势，采用双红外波长控制PL发射，建模动力学过程，展现光捕获等能力，使其成为先进生物标志物的优秀候选者。
AI 中文摘要
镧系掺杂上转换粒子（UCPs）因其优异的光稳定性、无毒性以及利用近红外激发实现深组织穿透且自发荧光可忽略不计，彻底改变了光学生物成像平台。然而，在不使用高功率激光的情况下，在嘈杂的生物介质中实现高对比度和亚衍射成像仍是一项挑战。本文报告了应用于铋掺杂UCPs的各种方案以应对其中一些挑战。与常规钇掺杂UCPs的光致发光（PL）发射相比，铋掺杂UCPs的总发射量子产率提高了三倍，红色发射提高了四倍。利用这一优势，设计了一种采用975nm和1064nm两个红外波长来选择性控制PL发射的方案。结果显示通过调节975nm激光功率可使PL有系统地淬灭或增强。将整体动力学建模为涉及三个能级的简化受激发射损耗过程。此外，该粒子具有亚衍射厚度，表现出光捕获能力以及表面功能化潜力以与多种生物样本进行特异性结合。这些研究表明铋掺杂UCPs是实现具有增强信噪比和亚衍射成像能力的先进生物标志物的优秀候选者。
英文摘要
Lanthanide-doped upconversion particles (UCPs) have revolutionized optical bioimaging platforms because of their excellent photostability, non-toxicity, and utilization of near-infrared excitation, which facilitates deep tissue penetration with negligible autofluorescence. However, it remains a challenge to achieve high-contrast and sub-diffraction imaging in noisy biological media, without using a high-power laser. Here, we report various protocols applied to bismuth-doped UCPs address some of these challenges. Compared to the photoluminescence (PL) emission of the regular Yttrium doped UCPs, we observe a three-fold increment in the quantum yield of the overall emission of bismuth-UCPs, and a four-fold increment, specifically, in red emission. Leveraging this advantage, we devise a protocol employing two infrared wavelengths, 975 nm and 1064 nm, to selectively control the PL emission. Interestingly, our results reveal two distinct regimes in which PL can be systematically quenched or enhanced, by adjusting the 975 nm laser power. We model the overall dynamics as a simplified stimulated emission depletion process involving three energy levels. In addition, the particle has a thickness under sub-diffraction, shows optical trapping ability, and potential of surface functionalization to enable specific conjugation with diverse biospecimens. These studies establish bismuth doped UCPs as an excellent candidate in accomplishing advanced biomarker operating with enhanced signal-to-noise ratio and sub-diffraction imaging capabilities.
Comments34 pages, 6 main figures, 8 supplementary figures
