The chemically prepared gold nanoparticles were characterized by TEM and the surface Plasmon band (SPB).
Fig. 2a shows the TEM image of the chemically prepared AuNPs, and the results indicate that spherical nano particles with an average diameter of 7.4 ± 1.3 nm were formed.
This result is in good agreement with the SPB, which had a maximum absorption wavelength at 517 nm (Fig. 2b) and is in agreement with the literature results for spherical nano particles with a diameter of less than 9 nm[37,38].