a) Confocal microscopy images of DS Red exp E. coli and activated Rhodamine 110 fluorophore in presence of NZ1. Composite images show homogeneous co-localization of biofilm and activated fluorophores. The panels are projections at 0º, 45º and 90º angle turning along Y-axis. The scale bars are 20 μm. b) Integrated intensity of Rhodamine 110 and DS Red biofilm after 1-hour incubation with NZ1. The x-axis is the depth of penetration of biofilms, where 0 μm represents the top layer and ~5.6 μm, the bottom layer. The y-axis, normalized fluorescence, is normalized intensity of red and green channel at the top layer to compare their localization. c) Cell viability of 3T3-Fibroblast cells after 24-hour incubation with NZ1-3 (0.1–2 μM). The data are average of triplicates and the error bars indicate standard deviations.