Fig. 1

Biosynthesis of IONPs (a) before synthesis and (b) after synthesis of Fe3O4 NPs but (e) before synthesis and (f) after synthesis of Fe2O3 NPs using Pseudomonas aeruginosa kb1 bacterial supernatant. Nano-iron pellets were collected in Petri dishes after centrifugation, (c) before and (d) after drying in an oven at 80 °C for 20 h for the Fe3O4 NPs, whereas they were collected (g) before and (h) after drying for the Fe2O3 NPs.