Innovative High-Performance Antimicrobial Agent and Dye Adsorbent Based on Magnetic/Copper Nanoparticles

Abstract

This study focuses on the synthesis and characterization of new magnetic nanoparticles complexed with copper, designated as Fe₃O₄@gly@cyclohexylidene-spiro[indoline-[1,3]dithiine]@Cu (FMNP). The structural confirmation of these nanoparticles was achieved through several techniques, including SEM imaging, VSM curves, XRD patterns, TGA and DTG curves, ICP-OES spectroscopy, and FT-IR spectrum analysis. Quantum mechanical studies were also conducted to precisely determine the complex’s position. These nanoparticles demonstrated antimicrobial properties against fungal, Gram-negative, and Gram-positive bacterial strains. The minimum fungicidal concentration (MFC) values ranged from 64 to 128 μg/mL, and the minimum bactericidal concentration (MBC) values varied between 8 and 256 μg/mL, indicating superior inhibitory effects on some microbial species compared to existing antibiotics. Furthermore, the FMNP nanoparticles were utilized in fabricating a crosslinked Oxidized Pectin-Fish Collagen Peptides hydrogel (FHGEL) aimed at adsorbing Congo red from aqueous solutions. The study of FHGEL’s adsorption capacity revealed that incorporating 0.03% FMNP significantly enhanced its ability to adsorb Congo red, showing a 3- to 4-fold increase compared to the hydrogel alone. The adsorption mechanism was attributed to dispersion mechanisms and the relaxation of macromolecules within a three-dimensional polymer network. This was supported by the FHGEL’s adsorption data fitting the R–P model, with the heterogeneity factor (n) value from the Sips isotherm model approaching 1.5, and a maximum adsorption capacity of 750.4 mg/g as predicted by the R–P model. The research findings indicate that all hydrogels adhere to the pseudo-second-order kinetics model, suggesting that FMNP could hold promising applications in the field of nanotechnology and environmental remediation.