Nanographenes: Ultrastable, Switchable, and Bright Probes for Super‐Resolution Microscopy

Abstract

Super‐resolution fluorescence microscopy has enabled important breakthroughs in biology and materials science. Implementations such as single‐molecule localization microscopy (SMLM) and minimal emission fluxes (MINFLUX) microscopy in the localization mode exploit fluorophores that blink, i.e., switch on and off, stochastically. Here, we introduce nanographenes, namely large polycyclic aromatic hydrocarbons that can also be regarded as atomically precise graphene quantum dots, as a new class of fluorophores for super‐resolution fluorescence microscopy. Nanographenes exhibit outstanding photophysical properties: intrinsic blinking even in air, excellent fluorescence recovery, and stability over several months. As a proof of concept for super‐resolution applications, we use nanographenes in SMLM to generate 3D super‐resolution images of silica nanocracks. Our findings open the door for the widespread application of nanographenes in super‐resolution fluorescence microscopy.

Single-molecule observation of diffusion and catalysis in nanoporous solids

“…However, their larger size in comparison to fluorescent molecules limits the application in many microand mesoporous systems (pore diameters ≤ 50 nm). Here, nanographenes hold great potential for SMLM as they are the happy medium between the small size of molecules and favorable photoemission properties of quantum dots [65].…”

Synthesis and Characterization of Dibenzo[<i>hi,st</i>]ovalene as a Highly Fluorescent Polycyclic Aromatic Hydrocarbon and Its π-Extension to Circumpyrene

“…With the view of applying DBOV as a uorophore for optical imaging, especially in SMLM, the blinking properties of 15b were investigated in collaboration with Xiaomin Liu, Mischa Bonn, and their colleagues. 27 DBOV 15b indeed demonstrated blinking with a blinking time of 87 ms, which is approximately 1.3 fold longer than that of Alexa 647 (69 ms), one of the most widely used uorophores for SMLM. Remarkably, the blinking of 15b could be observed under various environments, including under air and in a PS matrix, in stark contrast to Alexa 647, which needs a special buffer for blinking.…”

“…19,34 While open shell PAHs are highly interesting for spintronic and even quantum information technology applications, 35 closed shell PAHs with long wavelength absorption, strong uorescence and high chemical stability can be more useful for other applications, such as in (opto)electronics, 36 photonics, 37 and uorescence imaging. 27,38 The stability and possible open shell character of PAHs can be qualitatively assessed according to Clar s aromatic π sextet rule. 39 In general, a PAH with a given number of aromatic π sextets is more stable than its isomers with fewer aromatic π sextets.…”

“…26 DBOV exhibits strong red uorescence and stimulated emission, which renders it an interesting dye for light emitting devices, including lasers, 26 as well as for uorescence microscopy imaging. 27 Most of the PAHs with zigzag edges thus far synthesized have a combination of zigzag edges with armchair edges or bay regions. Representative exceptions are pyrene, coronene, 28 acenes, 19 anthanthrene, 29 and ovalene 17 (Figure 2), which can be considered classical examples of zigzag edged PAHs without any bay region, which we call zigzag PAHs in this account.…”

Spiers Memorial Lecture : Carbon nanostructures by macromolecular design – from branched polyphenylenes to nanographenes and graphene nanoribbons

“…110 Moreover, DBOV and other NGs, including HBC, were revealed by the group of Mischa Bonn to show fluorescence blinking on timescales useful for modern super-resolution microscopy, including single-molecule localization microscopy and minimal emission flux microscopy. 111 Remarkably, DBOV continued to blink in various environments, including air, and maintained blinking behaviour after 125 days of storage, in stark contrast to standard organic dyes such as Alexa 647. The latter requires a special buffer and stops blinking after a few hours.…”