Silver Nanoparticles Synthesis using Banana Peels Extract and Its in Silico Evaluation for Antibacterial Activity against Escherichia coli

Abstract

Metal nanoparticles (NPs) is widely applied in biomedical science. Silver nanoparticles (AgNPs) is one of the potential metal nanoparticles famous for its potent antibacterial properties. However, its detrimental consequences on human health have been a significant concern. In this study, AgNPs was synthesized using banana peels by environmentally friendly approach, and their antibacterial activity against Escherichia coli as well as mechanisms were studied in silico. Total phenolic content (TPC), total flavonoid content (TFC), and total tannin acid content (TTC) of the BPE were initially determined by extraction using aqueous and methanolic solutions. A disc diffusion test (DDT) against E. coli was used to confirm the antibacterial activity of the BPE and BPE-AgNPs. An in silico approach was used to conduct molecular docking research to assess the potential antibacterial mechanism of BPE phytochemicals with the proteins of E. coli. The phytochemical content analysis shows that flavonoid has the highest content in the aqueous and the methanol extract, with respective concentrations of 439.60±57.84 mg QE/g DW and 222.42±14.56 mg QE/g DW. According to the results of DDT, BPE-AgNPs demonstrated positive antibacterial activity, while BPE demonstrated negative result. Several flavonoid chemical compounds, including rutin, quercetin, myricetin, naringenin, apigenin, luteolin, morin, galangin, catechin, and chrysin, were examined for their ability to bind to E. coli proteins such penicillin-binding protein, dihydrofolate reductase, and glutamate racemase. Rutin with penicillin-binding protein demonstrated the highest binding affinity, with the lowest free binding energy of -9.96 kcal/mol and the inhibition constant of 0.05 µM. The in silico and molecular docking analysis demonstrated the ability of active components of banana peels to inhibit the activity of the E.coli proteins. These elements not only function as reducing and stabilising agents for AgNP synthesis but also prevent E. coli from growing, which is potential in future antibacterial uses.