Synthesis and photonics applications of afzelechin conjugated silver nanoparticles

The silver nanoparticles were synthesized, functionalized with afzelechin and characterized using UV-Visible spectroscopy. A difference of 20 nm was observed in surface plasmon resonance of bare and functionalized silver nanoparticles which indicates afzelechin conjugation with silver nanoparticles. The atomic force microscopy (AFM) technique was used for the determination of the size and morphology of synthesized silver nanoparticles. The afzelechin conjugated silver nanoparticles were spherical and their sizes ranged from 3 to 10 nm with an average size of 8 nm while the bare silver nanoparticles were also spherical and their sizes ranged from 3 to 10 nm with an average size of 6 nm. The average sizes were also calculated by fitting their UV-Visible absorption spectra. Fitting is based on the Mie and Mie Gans models, which deduced that afzelechin conjugated silver nanoparticles were 96.5% spherical and 3.5% spheroidal with an average size of 5 nm while bare silver nanoparticles were 100% spherical with an average size of 4 nm. Both the fitting model as well as the AFM results showed a difference of 3 nm between the sizes of afzelechin conjugated silver nanoparticles while 2 nm differences was observed for bare silver nanoparticles. The band gap energy of afzelechin conjugated silver nanoparticles and bare silver nanoparticles were calculated via Tauc’s equation and were found to be 5.1 eV and 5.4 eV, respectively. A difference of 0.3 eV was observed in band gap energies of afzelechin conjugated silver nanoparticles and bare silver nanoparticles.