Honey-assisted synthesis and properties of silver nanoparticles in aqueous solution and inside supramolecular aggregates. The Cassyopea® effect

Abstract

In this work we introduce supramolecular aggregates named Cassyopea®, acronym of combined and sustainable synthesis of payload-enriched aggregates from the method used for their preparation. Herein, Cassyopea® were described as reactors and carriers for silver nanoparticles (AgNPs) obtained from honey according to eco-friendly conditions. Spherical, monodisperse, and negatively charged NewAgNPs®, acronym of natural ecosustainable way AgNPs, having a mean size of 30 nm and high stability over time were prepared in aqueous solution. The successful synthesis of NewAgNPs® inside Cassyopea® was demonstrated by UV–vis spectroscopy, emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray (EDX) analysis. The protective effect of Cassyopea® on NewAgNPs® against the oxidation induced by H2O2 was kinetically determined in the Fenton-like reaction suggesting that the investigated nanoparticles tend to be located in the aqueous core of the investigated aggregates. Furthermore, microbiological assays revealed the tendency of Cassyopea® to preserve the biological activity of NewAgNPs® against Gram-positive and Gram-negative bacteria. The preparation of silver nanoparticles directly into supramolecular aggregates instead of their loading in preformed state is unprecedented, and the data reported for NewAgNPs® and Cassyopea® highlight promising applications in nanotechnology.