Highly Efficient Fluorescence Quenching with Graphene

Abstract

Fluorescence quenching is a powerful technique used to obtain information about the dynamic changes of proteins in complex macromolecular systems. In this work, graphene is shown to be a very efficient quencher of fluorescence molecules where the quenching effect was one order of magnitude higher than that of gold. The fluorescence intensity was distance-dependent where increasing the distance between the fluorescence molecule and the graphene surface from 4 to 7 nm increased the fluorescence intensity by a factor of 7.5. This type of distance dependence suggests a nonradiative nature in the energy transfer between the graphene and the fluorophore due to the excitation of an exciton.

Using the Plasmon Linewidth To Calculate the Time and Efficiency of Electron Transfer between Gold Nanorods and Graphene

“…This latter mechanism of an amplification of extrinsic local emitters seems, however, very unlikely given that we do not observe any detectable PL quenching in Figure 3D despite the fact that graphene is an excellent electron acceptor for small molecules over a wide range of energies. 53–55 For the one-photon PL mechanism of plasmon emission after interconversion between hot electrons and plasmon, the lack of intensity loss is not inconsistent and implies that back electron transfer from the graphene to the gold must be very fast as well, as indicated by the doubled arrow in Figure 4C. This fast back electron transfer also ensures that the nanorods do not become permanently charged, 2 consistent with the absence of a plasmon resonance shift, although charge induced effects could be offset by dielectric changes.…”

Scalable synthesis of WS 2 on graphene and h-BN: an all-2D platform for light-matter transduction

“…Self-organized photo-emitting/photoconductive patterns of WS 2 on epitaxial graphene As PL is quenched in WS 2 /graphene stacks because of enhanced electron transfer to gapless graphene [29], one might wonder whether the synthesized WS 2 films still presents a robust polarization conservation. To gain some insight into this, we also consider epitaxial graphene on SiC(0001) [30] as a perfect platform to investigate the optical properties of the synthesized WS 2 crystals.…”

Understanding and optimising the packing density of perylene bisimide layers on CVD-grown graphene

“…4 Raman spectra of 1 directly after deposition onto graphene often show a small fluorescence background and fluctuations in packing density. We attribute this to the formation of small areas of a 2nd layer or multilayers of 1, since the inherent fluorescence of these molecules 5 is only quenched in the immediate vicinity of the graphene substrate, 6 but can be detected with the Raman spectrometer in multilayers as increased background intensity. As shown in Figure S2c, this background and therefore multilayer formation can be significantly reduced by soaking the samples in de-ionized water for at least 5 minutes.…”

“…Since the isolation of single layer graphene by mechanical exfoliation 1 and the subsequent discovery and demonstration of its outstanding electronic 2 and mechanical 3 properties, graphene has attracted an extremely high level of interest. It has been proposed for numerous applications in electronics, 4 photonics, [5][6] sensing, 7 as well as gas barriers 8 and coatings. 9 However, for most of these applications it is necessary to introduce functional groups onto the graphene surface, e.g.…”