We designed and fabricated guided-mode resonance (GMR) gratings on indium-tin-oxide (ITO) thin film to generate a significantly enhanced local electric field for surface-enhanced Raman scattering (SERS) spectroscopy. Ag nanoparticles (NPs) were self-assembled onto the surface of the grating, which can provide a large amount of "hot-spots" for SERS sensing. The ITO gratings also exhibit excellent tolerance to fabrication deviations due to the large refractive index contrast of the ITO grating. Quantitative experimental results of 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) demonstrate the best enhancement factor of ~14× on ITO gratings when compared with Ag NPs on a flat ITO film, and the limit of detection (LOD) of DTNB is as low as 10 pM.
Keyphrases
- silver nanoparticles
- high resolution
- gold nanoparticles
- quantum dots
- energy transfer
- sensitive detection
- label free
- single molecule
- oxide nanoparticles
- raman spectroscopy
- air pollution
- highly efficient
- reduced graphene oxide
- room temperature
- risk assessment
- loop mediated isothermal amplification
- polycyclic aromatic hydrocarbons
- low cost
- tissue engineering