摘要
Many kinds of nano particles and organic dyes as fluorescent probes have been used in the stimulated emission depletion(STED)nanoscopy.Due to high toxicity,photobleaching and non-water solubility,these fluorescent probes are hard to apply in living cell imaging.Here,we reporta new fluorescence carbon dots(FNCDs)with high photoluminescence quantum yield(56%),low toxicity,anti-photobleaching and goodwater-solubility that suitable for live-cell imaging can be obtained by doping fluorine element.Moreover,the FNCDs can stain the nucleolusand tunneling nanotubes(TNTs)in the living cell.More importantly,for STED nanoscopy imaging,the FNCDs effectively depleted backgroundsignals and improved imaging resolution.Furthermore,the lateral resolution of single FNCDs size under the STED nanoscopy is up to 22.1 nm for FNCDs deposited on a glass slide was obtained.And because of their good water dispersibility,the higher resolution of single FNCDs sizein the nucleolus of a living cell can be up to 19.7 nm.After the image optimizati on steps,the fine fluoresce nee images of TNTs diameter with ca.75 nm resolution is obtained living cell,yielding a threefold enhancement compared with that in confocal imaging.Additionally,the FNCDs show excellent photobleaching resistance after 1,000 scan cycles in the STED model.All results show that FNCDs have significant potentialfor application in STED nanoscopy.
基金
We thank X.Peng(Shenzhen University)for great assistance in tunneling nanotubes of live cell.This work was partially supported by the National Key R&D Program of China(No.2018YFC0910600)
the National Natural Science Foundation of China(Nos.61975132,61775145,61525503,61620106016,61835009,and 81727804)
China Postdoctoral Science Foundation(No.2019M650211)
Guangdong Province Key Area R&D Program(No.2019B110233004)
Project of Department of Education of Guangdong Province(No.2015KGJHZ002/2016KCXTD007)
the Shenzhen Basic Research Project(Nos.JCYJ20170412110212234 and JCYJ20170412105003520)
the Natural Science Foundation of Shenzhen University(2019108).
