Copper- and Iron-Based Bio-Nanocomposites for Green Applications

Kottappara, Revathi; Pillai, Suresh C.; Vijayan, Baiju Kizhakkekilikoodayil

doi:10.1007/978-3-030-61985-5_2

Cited by 1 publication

(1 citation statement)

References 193 publications

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“…Other factors define the properties of NPs and, thus, their toxicity, such as chemical and electronic composition, structure, as well as topology [ 82 ]. Aggregation and concentration also influence toxicity, as they lead to an increase in size, as well as cellular age, temperature, pH, and reaction time, as indicated by the study conducted by Mahsa et al [ 83 ], where silver NPs lost their effectiveness after 48 h of contact with Staphylococcus aureus [ 3 , 84 , 85 ].…”

Section: Resultsmentioning

confidence: 99%

Comparative Effect of Antioxidant and Antibacterial Potential of Zinc Oxide Nanoparticles from Aqueous Extract of Nepeta nepetella through Different Precursor Concentrations

Fodil,

Serra,

Abdullah

et al. 2024

Materials

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Antibiotic resistance is a global health crisis caused by the overuse and misuse of antibiotics. Accordingly, bacteria have developed mechanisms to resist antibiotics. This crisis endangers public health systems and medical procedures, underscoring the urgent need for novel antimicrobial agents. This study focuses on the green synthesis of ZnO nanoparticles (NPs) using aqueous extracts from Nepeta nepetella subps. amethystine leaves and stems, employing different zinc sulfate concentrations (0.5, 1, and 2 M). NP characterization included transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD), along with Fourier transform infrared spectroscopy (FTIR) analysis. This study aimed to assess the efficacy of ZnO NPs, prepared at varying concentrations of zinc sulfate, for their capacity to inhibit both Gram-positive and Gram-negative bacteria, as well as their antioxidant potential using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. SEM and TEM results showed predominantly spherical NPs. The smallest size (18.5 ± 1.3 nm for leaves and 18.1 ± 1.3 nm for stems) occurred with the 0.5 M precursor concentration. These NPs also exhibited remarkable antibacterial activity against both Gram-positive and Gram-negative bacteria at 10 µg/mL, as well as the highest antioxidant activity, with an IC50 (the concentration of NPs that scavenge 50% of the initial DPPH radicals) of 62 ± 0.8 (µg/mL) for the leaves and 35 ± 0.6 (µg/mL) for the stems. NPs and precursor concentrations were modeled to assess their impact on bacteria using a 2D polynomial equation. Response surface plots identified optimal concentration conditions for antibacterial effectiveness against each species, promising in combating antibiotic resistance.

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