Sono-Biosynthesis and Characterization of AuNPs from Danube Delta Nymphaea alba Root Extracts and Their Biological Properties

Mihaela Cudalbeanu; David Peitinho; Francisco Silva; Rosa Marques; Teresa Pinheiro; Ana C. Ferreira; Fernanda Marques; António Paulo; Catarina F. Soeiro; Sílvia Andreia Sousa; Jorge Humberto Leitão; Aurel Tăbăcaru; Sorin Marius Avramescu; Rodica Mihaela Dinica; Maria Paula Cabral Campello

Key information

Authors:

Mihaela Cudalbeanu; David Peitinho; Francisco Silva; Rosa Marques; Teresa Pinheiro (Maria Teresa Ferreira Marques Pinheiro); Ana C. Ferreira (Ana Cristina Gomes Ferreira da Silva Parreira); Fernanda Marques (Fernanda Marujo Marques); António Paulo (António Manuel Rocha Paulo); Catarina F. Soeiro; Sílvia Andreia Sousa (Sílvia Andreia Bento da Silva Sousa Barbosa); Jorge Humberto Leitão (Jorge Humberto Gomes Leitão); Aurel Tăbăcaru; Sorin Marius Avramescu; Rodica Mihaela Dinica; Maria Paula Cabral Campello (Maria Paula Cordeiro Crespo Cabral Campello Aboim de Barros)

Published in

06/14/2021

Abstract

Root extracts from Danube Delta Nymphaea alba were used to prepare gold nanoparticles (AuNPRn) by reducing HAuCl4 at different pHs (6.4–8.4) using ultrasonic irradiation: an easy, cheap, eco-friendly and green approach. Their antibacterial and anticancer activities were evaluated against Staphylococcus aureus and Escherichia coli, and A2780 ovarian cancer cells, respectively. The AuNPRn were characterized concerning their phytoconstituents (polyphenols, flavonoids and condensed tannins) and gold content. All of the nanoparticles were negatively charged. AuNPRn exhibited a hydrodynamic size distribution ranging from 32 nm to 280 nm, with the larger nanoparticles being obtained with an Au/root extract ratio of 0.56, pH 7 and 10 min of sonication (AuNPR1), whereas the smallest were obtained with an Au/root extract ratio of 0.24, pH 7.8 and 40 min of sonication (AuNPR4). The TEM/SEM images showed that the AuNPRn had different shapes. The ATR-FTIR indicated that AuNPRn interact mainly with hydroxyl groups present in the polyphenol compounds, which also confirm their high antioxidant capacity, except for AuNPR2 obtained at pH 6.4. Among the AuNPRn, the smallest ones exhibited enhanced antimicrobial and anticancer activities.