Phytosynthesizing gold nanoparticles: Characterization, bioactivity, and catalysis evaluation

• Published in: Journal of molecular structure 2024-04, Vol.1302, p.137308, Article 137308
• Main Authors: Sobi, M. Amalin, Usha, D., Rajagopal, Rajakrishnan, Arokiyaraj, Selvaraj, Bindhu, M.R.
• Format: Article
• Language: English
• Subjects: Andrographis paniculata; Breast cancer; Centella asiatica; Gold nanoparticles; Lung cancer; Photocatalytic activity
• ISSN: 0022-2860
• DOI: 10.1016/j.molstruc.2023.137308

•Two medicinal plant extracts were used in the production of environmentally friendly AuNPs.•The effects of AuNPs on anti-bacterial, catalytic, photocatalytic and anticancer cell lines were examined.•The human lung and the breast cancer cell line growth and proliferation were inhibited.•AuNPs have catalytic properties for reducing 4-nitrophenol to 4-aminophenol.•Photocatalytic properties for degrading methyl orange and congo red were examined.•Strong antibacterial activity against gram-negative bacteria was identified. Worldwide health problem generally due to the lack of widespread and comprehensive early detection methods, the associated poor prognosis of patients diagnosed in later stages of the disease and its increasing incidence on a global scale. Indeed, the struggle to fight cancer is one of the greatest challenges of mankind. Centella Asiatica (CA) and Andrographis Paniculata (AP) are two medicinal plant extracts used in the environmentally friendly extracellular production of metallic gold nanoparticles. The size, shape, stability and crystallinity of the synthesized gold nanoparticles were characterised and various characterization methods were used; UV–Vis spectroscopy, Fourier Transform Infrared Spectroscopy, X-ray diffraction, Zeta potential, Selected Area Electron Diffraction, Energy Dispersive X-ray Spectroscopy, High Resolution Transmission Electron Microscopy equipped with elemental mapping in order to confirm the formation of gold nanoparticles. The TEM results showed that gold nanoparticles were mostly spherical in shape. Their effects on anti-bacterial, catalytic, photocatalytic and anticancer cell lines were examined. The MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] test was used to confirm the cytotoxic properties of both gold nanoparticles samples and the results showed that both the human lung cancer and human breast cancer cell line growth and proliferation were inhibited. Strong antibacterial activity against gram-negative bacteria and moderate antibacterial activity against gram-positive bacteria were identified. It has also been shown that gold nanoparticles have catalytic properties for reducing 4-nitrophenol to 4-aminophenol. By degrading the two dyes methyl orange and congo red in the presence of nano catalysts, the photocatalytic activity of synthesized nanoparticles has been assessed.