Abstract Upconversion nanoparticles (UCNPs) are a kind of unique optical material, that are able to emit ultraviolet (UV), visible or near infrared (NIR) luminescence upon NIR light excitation. Because of their excellent physic-chemical characters including enormous anti-Stokes spectral shift, high resistance to photobleaching, fairly long luminescent lifetime, excellent chemical stability, sharp emission band, and deep tissue penetration depth, UCNPs have become a useful tool in bioimaging, biosensing, as well as cancer therapy. In particularly, the emissions light from UCNPs can activate photosensitive molecules, which has the potential to realize the regulation of cell behaviors, including cell growth, adhesion and differentiation. This review consequently introduces the principle and achievements of UCNPs in biomedical field to the general readers for promoting both fundamental research and bio-applications of UCNPs. After the brief introduction of the physical mechanism of upconversion luminescence (UCL), we introduce several strategies to enhance the emissions brightness in detail, then discuss various biomedical applications of UCNPs.

中文翻译：

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上转换纳米材料：生物传感、治疗诊断和光调节平台

摘要 上转换纳米粒子（UCNPs）是一种独特的光学材料，能够在近红外光激发下发出紫外（UV）、可见光或近红外（NIR）发光。由于其优异的物理化学特性，包括巨大的反斯托克斯光谱漂移、高抗光漂白性、相当长的发光寿命、优异的化学稳定性、尖锐的发射带和深层组织穿透深度，UCNPs 已成为生物成像、生物传感的有用工具，以及癌症治疗。特别是UCNPs的发射光可以激活光敏分子，有可能实现细胞行为的调控，包括细胞生长、粘附和分化。因此，本综述向广大读者介绍了UCNPs在生物医学领域的原理和成果，以促进UCNPs的基础研究和生物应用。在简要介绍了上转换发光 (UCL) 的物理机制之后，我们详细介绍了几种增强发射亮度的策略，然后讨论了 UCNPs 的各种生物医学应用。