2.2. Instrumentation
The UV–vis spectra were recorded at room temperature using
a k-Helios SP Pye-Unicam spectrophotometer. Photoluminescence
spectra were recorded on a Perkin Elmer LS 50B luminescence
spectrophotometer. Transmission electron
microscopy (TEM) studies were performed using a JEOL
JEM 1200 electron microscope operating at an accelerating
voltage of 90 kV. For the TEM measurements, a drop of a
solution containing the particles was deposited on a copper
grid covered with amorphous carbon. After allowing the film
to stand for 2 min, the extra solution was removed by means
of blotting paper and the grid allowed drying before the measurement.
Fourier transform infrared (FTIR) spectra were recorded
at room temperature on a Nicolet 6700 FTIR
spectrometer. For the FTIR measurements of capped silver
nanoparticles, a small amount of silver nanoparticles (0.01 g)
dried at 60 C for 4 h was mixed with KBr to form a round
disk suitable for FTIR measurements. To obtain the FTIR
spectrum of the extract, an appropriate amount of the extract
was mixed with KBr. Thermogravimetric analyses were carried
out with a heating rate of 10 C/min using a Shimadzu DT-50
thermal analyzer. X-ray diffraction (XRD) pattern was obtained
using a Shimadzu XRD-6000 diffractometer with Cu
Ka (k= 1.54056 A ˚ ) to confirm the biosynthesis of AgNPs.
Atomic absorption was used to confirm the amount of AgNPs
formed for the concentrations used in antimicrobial assay.