Figure 3: Schematics and experimental results comparing different analyte collection concepts.

Diffusion (LEFT), a biased plate (CENTRE), and a nanolens-based collection concept (RIGHT) all use a constant 30 s long exposure to a gas mixture containing both charged and neutral BTs. The biasing conditions depicted in a lead to b, the recorded scanning confocal Raman intensity map of the characteristic Raman peak at 1,075 cm−1, and (c), corresponding spectra where the signal intensity for the biased substrates improves by a factor of 615. (b) Scale bar, 1 μm.