Green synthesis of gold nanoparticles from banana pith extract and its evaluation of antibacterial activity and catalytic reduction of malachite green dye

Anotace: In this paper, we report the synthesis of gold nanoparticles (BPAuNPs) using banana pith extract. Biosynthesized BPAuNPs were screened for phytochemicals coated over them and further characterized by UV-visible spectroscopy, FTIR, XRD and particle size analyser. UV-Visible spectrscopic analysis confirmed the production of BPAuNPs at 530 to 560 nm, where the colour change in the solution from light yellow to deep purple indicated the formation of BPAuNPs. FT-IR analysis confirmed the capping of BPAuNPs with organic residues like, proteins, amino acids and polyphenols present in the extract, which led to stabilization of BPAuNPs. Negative zeta values indicated the stability of BPAuNPs. XRD results prooved the crystalline nature of BPAuNPs. The synthesized BPAuNPs were tested for their antibacterial activity against both Gram positive (Bacillus subtilis) and negative (E.coli, Pseudomonas aeruginosa) bacteria with known antibiotic as control. BPAuNPs showed significant bacteriostatic effect. The BPAuNPs were found to have a positive catalytic activity of reduction of malachite green dye, which was confirmed by the time dependent reduction in absorbance maxima, it can be ascribed to the electron relay response.