Super-Resolution Imaging of Clickable Graphene Nanoribbons Decorated with Fluorescent Dyes

Abstract

The functional integration of atomically defined graphene nanoribbons (GNRs) into single-ribbon electronic device architectures has been limited by access to nondestructive high-resolution imaging techniques that are both compatible with common supports such as Si or Si/SiO wafers and capable of resolving individual ribbons in dilute samples. Conventional techniques such as scanning probe (AFM, STM) or electron microscopy (SEM, TEM) have been restricted by requisite sample preparation techniques that are incompatible with lithographic device fabrication. Here we report the design and synthesis of ultralong (∼10 μm) cove-type GNRs (cGNRs) featuring azide groups along the edges that can serve as a universal handle for late-stage functionalization with terminal alkynes. Copper-catalyzed click-chemistry with Cy5 fluorescent dyes gives rise to cGNRs decorated along the edges with fluorescent tags detectable by optical microscopy. The structures of individual dye-functionalized cGNRs spin-coated from a dilute solution onto transparent and opaque insulating substrates were resolved using diffraction-limited fluorescence microscopy and super-resolution microscopy (SRM) imaging techniques. Analysis of SRM images reveals an apparent width of cGNRs in the range 40-50 nm and lengths in excess of 10 μm, the longest GNRs imaged to date. Isolated cGNRs can even be distinguished from bundles and larger aggregates as long as the center-to-center distance is greater than the apparent width.

Polycyclic aromatic hydrocarbons in the graphene era

“…Composite electrodes comprising gold nanoparticles and the synthesized GNRs displayed a synergistic performance enhancement for the electrocatalytic reduction of CO 2 . Thereafter, Fischer and Xu et al [247] reported GNR 185 decorated with fluorescent dyes along the edges for super-resolution imaging. The synthesis relied on a key GNR 184 featuring pendant azide groups, which was used to attach the dye molecules by the copper-catalyzed azide-alkyne cycloaddition (CuAAC click reaction) (Figure 37(c)).…”

Reticular Growth of Graphene Nanoribbon 2D Covalent Organic Frameworks

“…Raman spectra of CHO-cGNRs show the characteristic signatures of cGNRs; a radial breathing like mode (RBLM) (253 cm -1 ), the D (1332 cm -1 ), and the G (1603 cm -1 ) peaks as well as overtone 2D, D+D ' , and 2D ' peaks ( Fig. 1D) 20,22,23 . An overlay of the respective IR spectra of poly-phenylene 5 and CHO-cGNR confirms the presence of aldehyde groups in the GNRs.…”

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

“…The synthesis of GNRs can be modified for incorporation of functional substituents to build in chromophores or stable free radicals, which will be useful later. [146][147][148][149][150] Additionally, GNRs can be subjected to further transformations by employing chlorination 58 and potentially hydrogenation, 151 as already established for NGs. Regarding scalability, the abovedescribed synthesis has been performed on a gram scale and can certainly be developed for even larger quantities.…”