STED超分辨显微技术具有成像速度快，可选择的荧光探针种类多，成像分辨率高等优势，具有十分广阔的应用前景。目前常用的STED成像探针以有机荧光分子为主，虽然有机荧光分子具有强荧光和良好的生物相容性，但是其抗光漂白性通常较差。而无机量子点则具有非常好的抗光漂白特性，但是由于无机量子点在强擦除光作用下会产生背景噪音，影响STED超分辨成像的效果。因此，本项目拟采用新型的CsPbX3钙钛矿量子点作为探针来研究其STED成像效果，首先构造CsPbX3@CaF2核壳结构的复合量子点，来提高其稳定性和生物兼容性；其次研究量子点在擦除光作用下产生背景噪音的根本原因，然后根据钙钛矿量子点的光谱特性系统地调整擦除光的波长，有效地削弱产生的背景噪音对其成像分辨率的影响；最后，采用相应的抗体修饰钙钛矿量子点去标记活细胞并进行STED超分辨成像，分析其成像效果，研究其作为超分辨探针的可行性。

STED nanoscopy have significant application prospect due to their fast imaging speed, various available probes and high imaging resolution. So far, the common used probes for STED nanoscopy were mainly focused on organic fluorescent molecular because of their strong photoluminescence and excellent biocompatibility, but the anti-photobleaching of organic fluorescent molecular was always very terrible. Comparatively, the quantum dots have excellent photobleaching, but noise signals was always generated for quantum dots under the effect of depletion laser, which will limit the resolution of STED nanoscopy. Therefore, we will use novel perovskite quantum dots as the probes for STED nanoscopy in this project. Firstly, we will enhance their stability and biocompatibility by designing a core-shell CsPbX3@CaF2 composite quantum dots. Then, we will investigate the generation mechanism of the noise signals and propose the solution to reduce it. Finally, we will label living cell by the novel quantum dots decorated by specific antibody and observe them by STED nanoscopy, to investigate the feasibility of application.