Microwave assisted green synthesis of pectin based silver nanoparticles and their antibacterial and antifungal activities.

Highlights • Ag NPs were prepared by the reaction of silver nitrate with alkali hydrolyzed pectin at microwave irradiation. • Small size spherical Ag NPs were produced with average sizes of 2.9 nm and 11.9 nm depending on microwave time. • Obtained Ag NPs colloidal solution were well stable with Zeta potential of near −40 mV. • MICs of Ag NPs against both E. coli and S. aureus were equally at 80–160 µg/ml. Abstract In this work, monodispersed silver nanoparticles (Ag NPs) were prepared by the reaction of silver nitrate with alkali hydrolyzed pectin at microwave irradiation. Two types of Ag NPs were obtained under the following conditions: 400 W of microwave power, 1 g/l NaOH, 2 g/l pectin, 10 mmol/l AgNO 3 , and irradiation time for 1 and 2 min, respectively. The zeta potential values of Ag NPs colloidal solutions were −39.6 and −38.7 mV, indicating that these nanoparticles were stable. Transmission electron microscopy (TEM) analysis revealed these spherical Ag NPs with an average size 2.90 and 11.94 nm, respectively. Ag NPs exhibited potent antibacterial and antifungal activities to against Escherichia coli , Staphylococcus aureus , and Aspergillus japonicus , and the minimum bactericidal concentrations (MIC) to against E. coli and S. aureus were equally at 80–160 µg/ml. In a word, this is a green, efficient, and cost-effective method for Ag NPs synthesis. [ABSTRACT FROM AUTHOR]