Biofilm Morphology and Composition Analysis

Scanning electron microscopy for biofilm was performed. The bacterial consortium control (absence of nanoparticles) and treated cells with 1 μg/ml of TiO₂-NPs in waste water medium was grown in 24 well microtitre plates and incubated at 37°C for 24 h. The samples were washed with 1x PBS after 24 h incubation and was fixed with 2.5% glutaraldehyde. The fixation step was further followed by dehydration steps with 20, 40, 60, 80 and 100% ethanol and dried overnight. The glass slides were fixed on the specimen mount with the help of carbon tape. To avoid surface charge interference, gold sputtering was executed in an argon atmosphere. Morphological analysis and surface elemental composition of the biofilm was performed with the help of SEM-EDX (S-400, HITACHI and Tokyo, Japan JEOL JSM-5510) [16 (link)].