Investigation of 1D siliver nanoparticle arrays for use as molecule concentration-specific SERS substrates

One-dimensional arrays of silver nanoparticles with a particle size of 10.5nm and interparticle spacing of 8.5nm were fabricated by depositing nanoparticles in gas phase on block copolymer self-assembled templates. The substrate showed a surface-enhanced Raman scattering (SERS) enhancement factor as high as 1 × 107 with good reproducibility and stability. The dependence of the average enhancement factor and the SERS intensity on the packing density of the analyte molecules were investigated. For a tiny amount of analytes in the range of 1 × 10-14 to 3 × 10-13 mol/mm2, the SERS signal showed a linear dependence on the molecule packing density on a logarithmic scale, with a slope of about 1.25. The substrates are promising for quantitative detection of trace level molecules.