Synthesis Of Gold Nanoparticles Using Leucas Aspera Extract For Multifunctional Applications
Gold nanoparticles (AUNPS) were synthesized from chloroauric acid in neutral pH medium at ambient conditions
using natural herbal plant Leucas aspera leaf extract as an effective reducing agent as well as capping agent. UV-Visible
analysis of the extract showed high intense peak at 373 nm and this wavelength was applied in HPLC analysis of the extract to
identify major components in the extract. The results revealed the presence of olmesaton, troxipide, bupropion,
n-(2-hydroxyethyl)-2-pyrrolidone, acrylamide, N-(1-oxo-1,3- dihydroisobenzofuran-5-yl)-3-phenyl and
2-[2-(1H-1,2,3-benzotriazol-1-yl)-N-[(4-methoxyphenyl) methyl] acetamido]-N-tert-butyl-2-(3,4,5-trimethoxyphenyl)
acetamide. Formation of AuNPs using the extract was monitored through UV-Vis surface Plasmon resonance (SPR) peak at
541 nm. The reduction of gold ions into AuNPs was observed by the change in colour of the reaction mixture from dark green
to dark brown. XRD results confirmed the existence of AuNPs. FT-IR analysis revealed the presence of reducing carbonyl
functional groups in the Leucas aspera leaf extract. HR-TEM images showed spherical morphology of AuNPs. The
synthesized AuNPs was coated on cotton fabric by pad-dry-cure method. The antibacterial efficiency of coated cotton fabric
was evidenced by the zone of inhibition against S. epidermidis (63%) and E. coli (37%). Ultraviolet protection factor (UPF)
value was calculated as 19, which indicated good protection against the penetration of UV-B rays. Synthesized AuNPs showed
cytotoxicity level of 50% death of HepG2 cells at a sample concentration of 103.9 μg/mL.
Index Terms- Aunps, antibacterial, cytotoxicity, Leucas aspera, UPF.