Fig. 3From: SnO2 nanostructure-based acetone sensors for breath analysisCopyright (2016) John Wiley and SonsPattern recognition based on PCA using sensor arrays (PS-SnO2 NTs, Pt-PS-SnO2 NTs, and Pt-SnO2 NTs). Reprinted from [81] with permission from John Wiley and Sons Back to article page