Iranian Journal of Chemical Engineering (IJChE)
Scientific Journal

Green Synthesis of AuNPs using Teucrium polium Extract: A Dual-Action Platform for Antimicrobial Activity and Phytochemical Enhancement

Articles in Press

Document Type : Regular Article

Authors

Samer Asadi 1
Ehsan Dahaz 2
Somayeh Lashgari 3

1 Department of Chemical Engineering, Petroleum University of Technology (PUT), Abadan, Iran

2 Department of Chemical Engineering, Kherad Institute of Higher Education, Bushehr, Iran

3 Iran Polymer and Petrochemical Institute, P.O.: 14965-115, Tehran, Iran

10.22034/ijche.2026.579473.1589
Abstract
This study presents the premier report of gold nanoparticle (AuNP) synthesis using Teucrium polium (T. polium) plant extract, investigating the antimicrobial activity of both aqueous and methanolic T. polium extracts and the synthesized AuNPs. Additionally, the effect of different concentrations of synthesized AuNPs on the phytochemical properties of T. polium plant extract was examined. The results of Ultraviolet-visible spectroscopy (UV-Vis spectroscopy), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared (FTIR) tests on AuNPs confirmed their synthesis. SEM and TEM images showed that the AuNPs were spherical in shape with an average size of 22.89 nm. The surface plasmon resonance (SPR) peak of the UV-Vis spectroscopy corresponding to the synthesized AuNPs appeared at 420 nm. The optimal pH of the reaction solution was also equal to 5. According to the results, the methanolic extract exhibited significantly higher antibacterial and antifungal activity compared to the aqueous extract, with the maximum inhibition zone diameters observed for Escherichia coli (14±1.4 mm) and Aspergillus Niger (15±0.7 mm). Moreover, the antimicrobial activity of AuNPs showed that these nanoparticles have relatively good ability to inhibit gram-negative bacteria, with the largest inhibition zone diameters observed for Escherichia coli (18±0.7 mm) and Aspergillus niger (20±0.9 mm). The antioxidant and reducing power activity (phenolic flavonoids content) of T. polium plant extract treated with different concentrations of synthesized AuNPs increased with increasing nanoparticle concentrations up to 60 ppm (IC50=9.94 µg/mL and reducing power= 16.85 mMFe2+/mg sample), and decreased at higher concentrations.

Keywords

AuNPs
T. polium plant extract
Antibacterial
Antifungal
Antioxidant activity
Reducing power
Subjects
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Iranian Journal of Chemical Engineering (IJChE)

Articles in Press, Accepted Manuscript
Available Online from 14 June 2026

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