Fig. 1: Raman spectra of graphene on different solid and liquid supports.

a Graphene-on-copper, free-standing graphene on a quantifoil grid, graphene at a water/air interface, graphene at a water/1-octanol interface, graphene at a water/cyclohexane interface, pure 1-octanol, pure cyclohexane and pure water. Laser excitation wavelength is 457 nm. b Graphene on a Si/SiO₂ wafer, free-standing graphene on a quantifoil grid, graphene at a water/air interface, graphene at a water/1-octanol interface, graphene at a water/cyclohexane interface, pure 1-octanol, pure cyclohexane and pure water. Laser excitation wavelength is 532 nm. c The Raman spectra of graphene at a water/1-octanol interface and of pure 1-octanol recorded at an excitation wavelength of 457 nm. The G and 2D peaks of graphene are distinguishable from the peaks of 1-octanol. d The Raman spectra of graphene at water/1-octanol interface and pure 1-octanol recorded at 532 nm wavelength. The G and 2D peaks of graphene are distinguishable from the peaks of 1-octanol (see the inset).