Optical nanoparticles are nowadays one of the key elements of photonics. They do not only allow optical imaging of a plethora of systems (from cells to microelectronics), but, in many cases, they also behave as highly sensitive remote sensors. In recent years, it has been demonstrated the success of optical tweezers in isolating and manipulating individual optical nanoparticles. This has opened the door to high resolution single particle scanning and sensing. In this quickly growing field, it is now necessary to sum up what has been achieved so far to identify the appropriate system and experimental set-up required for each application. In this review article we summarize the most relevant results in the field of optical trapping of individual optical nanoparticles. After systematic bibliographic research, we identify the main families of optical nanoparticles in which optical trapping has been demonstrated. For each case, the main advances and applications have been described. Finally, we also include our critical opinion about the future of the field, identifying the challenges that we are facing.

多光子成像具有零背景下可见光信号输出的优势，但传统多光子探针激发域值高、光稳定性差的问题使其在生物应用中受到限制。基于稀土上转换的无机纳米粒子可在相对较低的激发光功率密度下实现稳定的上转换发光，因而成为一种重要的多光子探针。随着成像技术的进步，对上转换纳米粒子的研究正在从聚集体形式向单颗粒水平发展。单颗粒研究上转换发光不仅有利于排除环境因素的干扰，并且呈现出一系列与聚集体研究不尽一致的理论成果。由于单颗粒研究平台更加接近于探针生物成像的工作环境，因此在这一水平下对上转换纳米粒子进行材料优化与物理机制分析更贴近实际应用。本文从多光子发光机制与材料出发，重点围绕着单颗粒水平下上转换纳米粒子近年来的研究成果与应用进展进行了综述，最后对其未来的研究方向进行了展望。

分别采用彩色相机和多光谱相机构建辐射测温系统，利用黑体炉进行温度模型标定实验，并基于BP神经网络对标定数据进行训练得到测温模型。通过蜡烛火焰的温度测量实验，验证了测温模型的可靠性，且结果显示多光谱成像测温系统的测温精度高于彩色相机测温系统。针对常规辐射成像测温系统空间分辨率不足的问题，采用多光谱相机结合显微镜搭建了显微测温平台，对高温热台内的单石油焦颗粒燃烧过程进行记录，得到了石油焦颗粒表面的温度分布以及随时间的温度变化过程。