| 초록 |
Nanoscale metallic gaps have been considered as one of the most efficient surface-enhanced Raman probes owing to junction plasmons created in a small space. Lithographic techniques (e.g., photolithography or electron beam lithography) are widely used to prepare such metallic gaps. Here we show how capillary bridge allows to create three-dimensional (3D) nanogaps. First, thin PDMS film is deposited onto glass slide. Then, the monolayer of gold nanoparticles is transferred onto both PDMS-deposited glass and bare glass slides. Upon the addition of a small water droplet of analyte solution between the two glass slides, capillary bridge is immediately formed. Due to the increase in both the numbers of hot spots and analyte with respect to a probed volume, the Raman signal of R6G is increased. The Raman enhancement factor over the relative distance between the two glass slides is systematically investigated by changing the volume of the water droplet. |
