FT-IR analysis:
Spectrophotometers are devices that determine the absorption or passage
of special radiant energy wavelengths (light) from an analyte in a
solution. Due to the difference in the number and arrangement of groups,
the double bonds of carbon atoms in each molecule absorb light at
specific wavelengths with a specific spectrum pattern. According to the
Beer-Lambert law, the light absorbed amount at this specific wavelength
is directly proportional to the chemical sample concentration [32].
In laboratories, a large part of the measurements is based on absorbance
reactions. The activity of most cholesterol, triglycerides, enzymes,
lipoproteins, creatinine, urea, sugar and a wide range of analytes with
research and clinical applications, drugs and metabolites can be
measured by spectrophotometry. Investigating the molecular structure,
identifying compounds, comparing structures and finding the maximum
absorption wavelength are other spectrophotometry applications in
research problems [32].
Figure 3 shows the FT-IR spectrum of VNPs@Salvia officinalis . In
the FT-IR results of metallic nanoparticles the peaks in 400 to 700
cm-1 usually attributes to metal-oxygen bonds.
Accordingly, for VNPs@Salvia officinalis , the peaks at 462, 538,
and 725 cm-1 can be assigned for V-O bond. Similar
peaks with a little difference in wavenumbers have been reported for
green synthetic vanadium nanoparticles [32]. There are many points
of similarity between vanadium nanoparticles spectrum and that of plant
extract. The peaks at 3205 m-1 (of O-H), 1424 to 1665
cm-1 (C=C and C=O s), and 1120 cm-1(for the stretching vibration of C‐O), which belong to various
functional groups, reveal the linkage of different organic compounds to
the surface of VNPs@Salvia officinalis . These compounds have been
reported as Salvia officinalis secondary metabolites previously
[7-9].