Effect of the number of passes: AgNO
2.5 10-2M. Left: FESEM images of Ag nanoparticles printed with WE ink, 1,000 dpi, variable number of passes of the printhead on the silicon substrate, 1 to 6. Center: inter-particle gap distribution for 1 and 6 passes. Histograms are normalized with respect to the total number of counts. Right: SERS spectra of Cy5 (10-6 M) adsorbed on the same six lines.