AI 中文总结
本研究发现单个镧系掺杂纳米晶体内数千个镧系离子的上转换发光存在可调控的集体闪烁，阐明其机制并实现1.2纳米分辨率的超分辨成像，为相关领域提供新策略。
AI 中文摘要
荧光闪烁通常被视为稳定发射体的限制因素，但它可实现超分辨定位显微技术，并作为量子发射体的光物理状态及其与局部环境相互作用的多功能报告因子。然而，传统闪烁发射体通常是具有斯托克斯位移荧光的单量子系统，易受自发荧光背景、信号微弱及长时间激发下不可逆光降解的影响。相比之下，单个镧系掺杂上转换纳米晶体是有效的无背景反斯托克斯发射体，且表现出较强的抗光降解能力，但由于单个纳米晶体内存在大量不相关的发射镧系离子集合，通常被认为是非闪烁的。在此，我们报告了单个纳米晶体内数千个镧系离子的上转换发光中集体闪烁的发现与调控。该闪烁的开-关强度比超过10，持续时间超过15小时（超过10000个周期）且无明显光降解，可通过调节激发功率进行可逆调控。我们阐明了一种通用的、与激活剂无关的上转换闪烁机制，其中通过协同多离子过程随机产生的单个猝灭剂可拦截Yb3+敏化剂网络内的离域激发能，使整个纳米晶体变暗。得益于高对比度、长期光稳定闪烁及无背景发射，我们实现了稳健的超分辨定位显微技术，以1.2纳米的分辨率解析聚集体中的单个纳米晶体。本研究为在光稳定多发射体纳米系统中实现和调控集体闪烁建立了通用策略，为纳米科学、生物成像和量子技术开辟了新机遇。
英文摘要
Fluorescence blinking, often regarded as a limitation for stable emitters, can enable super-resolution localization microscopy and serve as a versatile reporter of the photophysical states of quantum emitters and their interactions with local environment. However, conventional blinking emitters are typically single quantum systems with Stokes-shifted fluorescence, making them susceptible to autofluorescence background, weak signal, and irreversible photodegradation under prolonged excitation. In contrast, single lanthanide-doped upconversion nanocrystals are effectively background-free anti-Stokes emitters and demonstrate robust resistance to photodegradation, yet they are generally considered non-blinking owing to the presence of a large ensemble of uncorrelated emitting lanthanide ions within a single nanocrystal. Here we report the discovery and control of collective blinking in the upconversion luminescence of thousands of lanthanide ions within a single nanocrystal. The blinking exhibits on-off intensity ratio exceeding 10, persists for over 15 hours (over 10,000 cycles) without discernible photodegradation, and can be reversibly controlled by adjusting the excitation power. We elucidate a universal, activator-independent upconversion blinking mechanism, whereby a single quencher, stochastically generated via a cooperative multi-ion process, can intercept delocalized excitation energy within the Yb3+ sensitizer network and darken the whole nanocrystal. Benefiting from the high-contrast, long-term photostable blinking and background-free emission, we achieve robust super-resolution localization microscopy that resolves individual nanocrystals in aggregates with 1.2 nm precision. This work establishes a general strategy to realize and control collective blinking in photostable multi-emitter nanosystems, opening new opportunities in nanoscience, bioimaging, and quantum technologies.
Comments25 pages; 10 figures
