Dual-Labeled Graphene Quantum Dot-Based Förster Resonance Energy Transfer Nanoprobes for Single-Molecule Localization Microscopy

[Image: see text] Single-molecule localization microscopy (SMLM)-based super-resolution imaging techniques (e.g., photoactivated localization microscopy (PALM)/stochastic optical reconstruction microscopy (STORM)) require that the employed optical nanoprobes possess fluorescence intensity fluctuations under certain excitation conditions. Here, we present a dual-labeled graphene quantum dot (GQD)-based Förster resonance energy transfer (FRET) nanoprobe, which is suitable for SMLM imaging. The nanoprobe is constructed by attaching Alexa Fluor 488 (AF488) and Alexa Fluor 568 (AF568) dye molecules onto GQDs. Experimental results confirmed the FRET effect of the nanoprobes. Moreover, under a single 405 nm excitation, the FRET nanoprobe exhibits excellent blinking behavior. SMLM imaging of microtubules in MRC-5 cells is realized. The presented nanoprobe shows great potential in multicolor SMLM-based super-resolution imaging.