Sugar-Derived Carbon Dots with Variable Fluorescence Blinking Property as a Super-Resolution Imaging Probe

Single-molecule localization microscopy (SMLM) is a powerful technique for breaking the diffraction limit of a light microscope and visualizing the structural details on a nanometer length scale. However, SMLM requires a probe with fluorescence blinking property, and development of a photostable probe with a tunable blinking cycle, high photon count, and low duty cycle is critical. Herein, we report a series of carbon dots (CDs) with variable fluorescence blinking properties that are derived from carbonization of different sugar molecules. We found that the fluorescence blinking property of reducing-sugar-derived CDs differs from that of nonreducing-sugar-derived CDs due to different surface functionalities and structural defects. These CDs have been used for SMLM-based single-particle imaging with a localization precision of 12-28 nm and a resolution of 54-62 nm, and more defective CDs offer better localization precision. The glucose-derived CDs are used for SMLM-based imaging of lysozyme fibrils with 61 nm resolution. This result suggests that CDs with varied fluorescence blinking parameters can be derived for super-resolution imaging applications.