Study of antibacterial and antioxidant activities of silver nanoparticles synthesized from Tradescantia pallida (purpurea) leaves extract

Abstract

This study defined a facile, inexpensive, and benign method to fabricate silver nanoparticles (AgNPs) using Tradescantia pallidum var. purpurea aqueous leaves extract for the first time. A UV–vis spectrum showed that the evaluated extract was promising for green synthesis of the SNP, with the highest peak of absorption between 450 and 550 nm. The phytochemicals present in the plant extract acts as capping and stabilization agent were confirmed by FTIR analysis. EDX proved the presence of Ag while SEM confirmed the AgNPs with the spherical shape. TEM revealed the average particle size was 23 nm. Additionally, AgNPs exhibited significant antibacterial activity and turbidimetry analysis showed MIC and MBC was in range of 25–100 µg/mL against both Gram positive and Gram-negative bacteria in Luria Bertani broth cultures. The AgNPs exhibited potent antibacterial activity against gram-positive bacteria, with a ZOI of 12 ± 0.25 mm produced against BacillusB subtilis showed the largest zones of inhibition, which were greater than the positive control (cefotaxime). The MIC values were 50 µg/mL for Pseudomonas aeruginosa, 25 µg/mL for Staphylococcus aureus and Escherichia coli, and 100 µg/mL for B. subtilis, confirming their significant antibacterial action. AgNPs inhibited the DDPH free radical scavenging activity with an IC₅₀ = 91.87 µg/mL. It is believed that these AgNPs play a crucial role in determining the therapeutic potential of T. pallida due to their biological efficacy.

Graphical Abstract

Keywords:

• Green synthesis
• silver nanoparticles
• Tradescantia pallida
• antibacterial activity
• minimum inhibitory concentration
• antioxidant activity

Acknowledgments

One of the authors, Romana Naaz, would like to express her gratitude to the University Grants Commission (UGC), New Delhi for providing financial support in the form of non-NET grants. The TEM facility was provided by All India Institute of Medical Science (AIIMS), while the extra experimental facility was supported by the Central Instrumentation Facility (CIF), Jamia Millia Islamia.

Author contributions

Romana Naaz: Conceptualization; Methodology; Formal analysis and investigation; Writing-original draft preparation. Vasi Uddin Siddiqui: Writing-review and editing; Formal analysis and investigation. Amina Ahmed: Investigation. Sami Ullah Qadir: Writing-review and Editing. Weqar Ahmad Siddiqi: Supervision.

Disclosure statement

The authors declare that they have no competing financial interests or known personal limitations that would impact the findings of this study.