Silver ion loaded 3-aminopropyl trimethoxysilane -modified FeO nanoparticles for the fabrication of carrageenan-based active packaging films.

FeO nanoparticle loaded with silver ion was prepared as a more efficient, safer, and less environmentally hazardous silver-based antibacterial nanomaterial. The FeO nanoparticle was modified using 3-aminopropyl trimethoxysilane (APTMS) to enhance the silver ion adsorption capacity and antibacterial activity. Silver ions were adsorbed on pristine FeO and FeO@NH to enhance antibacterial activity. Energy dispersive spectroscopy (EDS) results showed that FeO adsorbed 2.74 wt% of Ag, whereas FeO@NH adsorbed 9.88 wt%. Pristine FeONP, silver ion loaded FeO (FeO-Ag), and silver ion loaded FeO@NH (FeO@NH-Ag) were used to manufacture carrageenan-based composite films. Compared with FeO-Ag, FeO@NH-Ag exhibited stronger antimicrobial activity against E. coli (8.82 vs. 5.02 log reduction) and L. monocytogenes (10.09 vs. 3.93 log reduction). While the addition of FeO significantly reduced the WCA of the carrageenan films from 61.1 ± 5.4 ° to 37.2 ± 2.1 °, the additions of FeO-Ag and FeO@NH-Ag reduced the WCA of the film to a lesser extent (56.9 ± 4.6 ° and 56.9 ± 4.6 °, respectively). FeONP also improved the thermal stability of carrageenan over FeO@NH-Ag (22 °C vs. 13 °C) and UV blocking properties (T, 0.1 ± 0.0 % vs. 3.3 ± 1.5 %).