Ultrasmall silica nanospheres based blinking nanoprobes for optical super resolution imaging

Abstract Single-molecule localization-based super-resolution imaging technology provides a powerful tool for research in the nanoscale field. The properties of organic fluorescent probes have a decisive significance for the quality of super-resolution imaging. Here, we propose an ultrasmall silica nanospheres based blinking nanoprobe for single molecule localization imaging. The blinking nanoprobe is fabricated by attaching fluorophores onto the ultrasmall silica nanospheres and it shows excellent features in three ways. First, it has stable chemical properties and good biocompatibility. Second, it shows a sustainable and excellent fluorescence switching behavior, which is suitable for long-term super-resolution imaging. Third, it possesses a better localization precision (20–25 nm) than the fluorophore itself. To examine the application of the nanoprobe, breast cancer cell (SKBR3) derived exosomes are used as the target. By attaching HER2 aptamers onto the silica nanospheres, super-resolution imaging of the exosomes is realized. Such a new strategy for the preparation of super-resolution nanoprobes has a great potential for further exploring the biological functions of nanoscale biomarkers.