Biosynthesis of Silver Nanoparticles Functionalized with Histidine and Phenylalanine Amino Acids for Potential Antioxidant and Antibacterial Activities

Gemechu Shumi; Taye B Demissie; Rajalakshmanan Eswaramoorthy; Raji Feyisa Bogale; Girmaye Kenasa; Tegene Desalegn

doi:10.1021/acsomega.3c01910

Biosynthesis of Silver Nanoparticles Functionalized with Histidine and Phenylalanine Amino Acids for Potential Antioxidant and Antibacterial Activities

ACS Omega. 2023 Jun 26;8(27):24371-24386. doi: 10.1021/acsomega.3c01910. eCollection 2023 Jul 11.

Authors

Gemechu Shumi¹, Taye B Demissie², Rajalakshmanan Eswaramoorthy^{1

3}, Raji Feyisa Bogale⁴, Girmaye Kenasa⁵, Tegene Desalegn¹

Affiliations

¹ Department of Applied Chemistry, School of Natural Science, Adama Science and Technology University, Adama 1888, Ethiopia.
² Department of Chemistry, University of Botswana, P/bag UB 00704, Gaborone, Botswana.
³ Department of Biomaterials, Saveetha Dental College, and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai 600 077, India.
⁴ Department of Chemistry, College of Natural and Computational Science, Wollega University, Nekemte 395, Ethiopia.
⁵ Department of Biology, College of Natural and Computational Science, Wollega University, Nekemte 395, Ethiopia.

Abstract

Due to biochemically active secondary metabolites that assist in the reduction, stabilization, and capping of nanoparticles, plant-mediated nanoparticle synthesis is becoming more and more popular. This is because it allows for ecologically friendly, feasible, sustainable, and cost-effective green synthesis techniques. This study describes the biosynthesis of silver nanoparticles (AgNPs) functionalized with histidine and phenylalanine using the Lippia abyssinica (locally called koseret) plant leaf extract. The functionalization with amino acids was meant to enhance the biological activities of the AgNPs. The synthesized nanoparticles were characterized using UV-Visible absorption (UV-Vis), powder X-ray diffraction (pXRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy. The surface plasmonic resonance (SPR) peak at about 433 nm confirmed the biosynthesis of the AgNPs. FTIR spectra also revealed that the phytochemicals in the plant extract were responsible for the capping of the biogenically synthesized AgNPs. On the other hand, the TEM micrograph revealed that the morphology of AgNP-His had diameters ranging from 5 to 14 nm. The antibacterial activities of the synthesized nanoparticles against Gram-positive and Gram-negative bacteria showed a growth inhibition of 8.67 ± 1.25 and 11.00 ± 0.82 mm against Escherichia coli and Staphylococcus aureus, respectively, at a concentration of 62.5 μg/mL AgNP-His. Moreover, the nanoparticle has an antioxidant activity potential of 63.76 ± 1.25% at 250 μg/mL. The results showed that the green-synthesized AgNPs possess promising antioxidant and antibacterial activities with the potential for biological applications.