Synthesis and Characterization of TiO 2 Nanoparticle and Checking …
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2.2 Characterization
Before drying the solution, the supernatant was collected that contained suspended
nanoparticles. The collected supernatant was centrifuged at 10,000 rpm for 10 min,
around 200 µl of this was added to 1800 µl of double-distilled water. The diluted
solution was further analyzed using DLS (dynamic light scattering) for the estimation
of average nanoparticle size. The same solution sample was used in the UV–vis
spectrophotometer for absorption studies.
2.3 Dye Degradation
For dye degradation test, around 1 ml of bromothymol blue (BPB) dye was diluted
with 50 ml of double-distilled water and aliquoted to three 1.5-ml microcentrifuge
tubes each containing 2 ml of diluted dye solution. To this dye solution, 20 mg of
nanopowder was added to two tubes, whereas the third was mentioned as control
without nanopowder. Out of three tubes, two were exposed to sunlight (one having
nanopowder and one without) and the third was put in the dark having nanopowder.
In another set of experiments, different concentrations of nanopowder, i.e., 20 mg,
40 mg, 60 mg, were added to three tubes each containing 2 ml of diluted dye solution
to check the effect of concentration of nanopowder on the degradation of dye.
2.4 Antimicrobial Test
2.4.1 Antimicrobial Effect of TiO 2
The antimicrobial effect of TiO 2 was analyzed using Escherichia coli and Staphylococcus aureus. Overnight-grown culture of E. coli and S. aureus was added to 100 ml
of LB nutrient broths without and with various concentrations of TiO 2 nanoparticles, i.e., 0 µg/ml, 10 µg/ml, 20/ml, 40 µg/ml, 60 µg/ml, 80 µg/ml, 100 µg/ml and
incubated at 37 °C. The optical density was taken after the time interval of 25 min
at 600 nm and a graph was plotted.
2.4.2 Antimicrobial Efficiency of TiO 2 Nanoparticle by Agar Diffusion
Assay
On LB agar plate, 100 µl of bacterial culture was spread plated and five round disks
were placed. To each disk, 10 µl of different concentrations of TiO 2 nanoparticles,
i.e., 0%, 1%, 1.5%, 2%, and 2.5% was added. The zone of inhibition was measured
after 24 h of incubation of plates at 37 °C.
319
2.2 Characterization
Before drying the solution, the supernatant was collected that contained suspended
nanoparticles. The collected supernatant was centrifuged at 10,000 rpm for 10 min,
around 200 µl of this was added to 1800 µl of double-distilled water. The diluted
solution was further analyzed using DLS (dynamic light scattering) for the estimation
of average nanoparticle size. The same solution sample was used in the UV–vis
spectrophotometer for absorption studies.
2.3 Dye Degradation
For dye degradation test, around 1 ml of bromothymol blue (BPB) dye was diluted
with 50 ml of double-distilled water and aliquoted to three 1.5-ml microcentrifuge
tubes each containing 2 ml of diluted dye solution. To this dye solution, 20 mg of
nanopowder was added to two tubes, whereas the third was mentioned as control
without nanopowder. Out of three tubes, two were exposed to sunlight (one having
nanopowder and one without) and the third was put in the dark having nanopowder.
In another set of experiments, different concentrations of nanopowder, i.e., 20 mg,
40 mg, 60 mg, were added to three tubes each containing 2 ml of diluted dye solution
to check the effect of concentration of nanopowder on the degradation of dye.
2.4 Antimicrobial Test
2.4.1 Antimicrobial Effect of TiO 2
The antimicrobial effect of TiO 2 was analyzed using Escherichia coli and Staphylococcus aureus. Overnight-grown culture of E. coli and S. aureus was added to 100 ml
of LB nutrient broths without and with various concentrations of TiO 2 nanoparticles, i.e., 0 µg/ml, 10 µg/ml, 20/ml, 40 µg/ml, 60 µg/ml, 80 µg/ml, 100 µg/ml and
incubated at 37 °C. The optical density was taken after the time interval of 25 min
at 600 nm and a graph was plotted.
2.4.2 Antimicrobial Efficiency of TiO 2 Nanoparticle by Agar Diffusion
Assay
On LB agar plate, 100 µl of bacterial culture was spread plated and five round disks
were placed. To each disk, 10 µl of different concentrations of TiO 2 nanoparticles,
i.e., 0%, 1%, 1.5%, 2%, and 2.5% was added. The zone of inhibition was measured
after 24 h of incubation of plates at 37 °C.