Nanoplasmonic pillars engineered for single exosome detection (a) Picture of the 25.4 mm diameter LSPRi sensor chip. (b) Scanning electron microscope image of the device for a 20 × 20 array, with a pitch size of 600 nm scale bar: 1 μm. (c) Image of sixteen arrays, each consisting of 400 plasmonic nanopillars in a 20 × 20 square lattice and 500 nm pitch, scale bar: 10 μm. (d) False coloured SEM image of a 10 × 10 nanopillar array, scale bar: 1 μm. (e) High-magnification false-coloured SEM image showing a detailed view of individual nanopillars, scale bar: 200 nm. (f) Picture illustrating the size matching of individual nanopillars diameter (d = 90 nm) to that of exosomes (~50 nm < d < 200 nm). (Reproduced from Raghu D. et al. [87]. Copyright 2018, PLoS ONE).