Biosynthesis of Gold Nanoparticles Using Sambiloto Leaf Extracts and its Characteristics

Gold nanoparticles (AuNPs) have been successfully synthesized using aqueous sambiloto ( Andrographis Paniculata Ness ) leaf extract as a reducing agent. This method of synthesizing nanoparticles is called biosynthesis. Characterization was carried out using various techniques including UV-Vis, FTIR, and TEM. The results showed that the optimal synthesis ratio, i.e., AuCl 3 solution : sambiloto leaf extract, was 30 µl : 10 ml with a synthesis rate of 0.159 a.u./h. The characteristic of the gold nanoparticles synthesized is that the surface Plasmon resonance (SPR) wavelength is 529.00 nm; it was stable after 4 hours of synthesis and stayed until 24 hours at an SPR wavelength of 527.00-531.50 nm. The functional groups formed include O-H, aliphatic C-H, C=O stretch, aromatic C=C stretch, and C-O stretch. The size of the nanoparticles is in the range of 1-20 nm.