Surface-enhanced Raman spectroscopy of nanodiamond particles on silver

Abstract

Surface-enhanced Raman scattering was applied to study the nanodiamond with particles’ sizes 100 and 5 nm, positioned on silver (Ag) substrate using high focused laser beam acceleration method. The nanodiamond particles suspended in distilled water were accelerated by a near infrared laser beam and attached to an Ag foil serving as the target. This allows the nanodiamond particles to be ordered, positioned, and to penetrate deep into Ag. The nanodiamond–Ag surface structure after nanoparticles∕laser beam treatment was analyzed using micro-Raman spectroscopy and scanning electron microscopy. Strong interaction between the nanodiamond and Ag surface can be achieved, which allows us to observe surface-enhanced Raman scattering (SERS). The most significant enhancement observed for carbon was trans-polyacetylene bands in addition to the D and G bands. The enhancement can achieve orders in magnitude both for 100 and 5 nm nanodiamonds. The selective enhancement of some composite band intensity, a characteristic feature of SERS referred to as the blinking effect, was also observed.

785 nm Raman Spectroscopy of CVD Diamond Films

“…Without further information, it is not possible at this stage to state which of the above (if any) are responsible for the Raman features we see. Experiments to deliberately take SERS spectra from diamond nanoparticles [21] and films [22,23,24] involve many preparation steps and are difficult to perform, but yield spectra that look very similar to ours, with a plethora of sharp peaks in the range 400-3000 cm -1 that been assigned as various types of unspecified sp 2 carbon species. These Raman lines are often as intense or more intense than the diamond zone-centre line, which is very surprising, given the relatively large amount of material present in the several µm of diamond film compared to that present at the interface.…”

785 nm Raman spectroscopy of CVD diamond films

“…Furthermore, one well known feature of SERS is the instability of the spectra, with peaks 'blinking' in intensity with time [20]. Experiments to deliberately take SERS spectra from diamond nanoparticles [21] and films [22,23,24] involve many preparation steps and are difficult to perform, but yield spectra that look very similar to ours, with a plethora of sharp peaks in the range 400-3000 cm -1 that been assigned as various types of unspecified sp 2 carbon species. But SERS relies on the excitation of surface-plasmon resonances in metal (usually Ag) films or nanoparticles that have been evaporated onto the surface, which then efficiently couple energy into the nearby film or particle of interest, resulting in huge enhancement of its Raman signal.…”

Blue–green luminescence and SERS study of carbon‐rich hydrogenated amorphous silicon carbide films with multiphase structure

“…Surface enhanced Raman scattering (SERS) is a very powerful Raman technique, being able to provide a spectral intensity enhancement by orders of magnitude. The phenomenon occurs when adsorbing the target molecules onto nanometer‐sized roughened metal (Ag, Au, Cu, and some others) surface, or in colloids of metals 9, 10. The dominant mechanism of this enhancement is surface plasmon resonance (SPR) supported by nanostructured metals.…”

“…The dominant mechanism of this enhancement is surface plasmon resonance (SPR) supported by nanostructured metals. SERS from nanodiamond films, diamond‐like carbon (DLC) films and a‐C:H films has been investigated by several groups 9–13, while SERS from a‐Si 1− x C x :H has not been reported yet. As the structure of the carbon‐rich a‐Si 1− x C x :H is close to that of a‐C:H, the Raman and SERS spectrum can be analyzed relative to that of a‐C:H. And the conventional Raman signal of carbon‐rich a‐Si 1− x C x :H films is low and is interfered by the silicon substrates in this case.…”