1Research Scholar, Department of Botany, Government Arts College, Nandanam, Chennai
2Assistant Professor, Department of Microbiology, Mohamed Sathak College of Arts and Science, Chennai
3Assistant Professor, Department of Biotechnology, Alpha Arts and Science College, Chennai
4Assistant Professor, Department of Botany, Government Arts College, Nandanam, Chennai
Corresponding Author: Dr. S. Malathy, Department of Botany, Government Arts College, Nandanam, Chennai. Email: professormalathy@gmail.com
This research work reports about the eco-friendly synthesis of cobalt oxide nanoparticles (Co₃O₄ NPs) with excessive reduction potential from marine seagrass, Thalassia hemprichii, possessing plenty of bioactive constituents. The green synthetic strategies for producing environment-friendly nanomaterials and nanomaterial-based biomedical devices is the core objective. FTIR, XRD, TEM and SEM were used to characterize the synthesized Co₃O₄ NPs for their structural and morphological properties. FTIR spectra indicated functional groups of Co₃O₄ NPs interacting with metal–oxygen bonds, validating successful nanoparticle formation. XRD confirmed the crystalline cubic spinel structure of Co₃O₄ nanoparticles with an average crystallite size of ~20–40 nm. The crystalline structure was confirmed, and the average particle size was found to be in the range of 45–52 nm. The in vitro bioactivities of the nanoparticles were evaluated, and the nanoparticles showed strongly dose-dependent free radical-scavenging activity as evidenced by DPPH and nitric oxide (NO) scavenging activities. Co₃O₄ NPs showed 89% DPPH scavenging at 100 µg/mL with IC₅₀ = 42.93 µg/mL, comparable to seagrass extract (76.9%, IC₅₀ = 42.40 µg/mL) and BHT (IC₅₀ = 42.38 µg/mL). In nitric oxide assays, the NPs displayed dose-dependent inhibition, confirming effective free-radical scavenging capacity. The antibacterial activity of Co₃O₄ NPs was also assessed by the well diffusion method against pathogenic bacteria Streptococcus mutans, Pseudomonas aeruginosa, Bacillus subtilis, and Escherichia coli. Co₃O₄ NPs showed strong antibacterial activity with larger inhibition zones against both E. coli and B. subtilis. and strains compared to the seagrass extract. The enhanced efficacy highlights the potential of NPs as effective antimicrobial agents. This research emphasizes the novelty of marine plant extracts for the use as sustainable reducing and stabilizing agents in the synthesis of nanoparticles with respect to environmentally-friendly chemical routes. These results proposed that as-prepared green-synthesized Co₃O₄ NPs can be as potent antioxidants and antibacterial agents for biomedical and environmental uses.
Key Words: Co₃O₄ NPs, Thalassia hemprichii, Antioxidant activity, Antibacterial Activity, Escherichia coli
How to cite this article: Muthusamy S, Nagarajan Y, Shylee ML, Malathy S. Cobalt Oxide Nanoparticles Synthesized from Thalassia hemprichii Extract: Antioxidant and Antibacterial Potentials. Int J Drug Deliv Technol. 2026;16(11s): 379-391. DOI: 10.25258/ijddt.16.11s.36
Source of support: Nil.
Conflict of interest: None