Green synthesis, characterization and functional validation of bio-transformed selenium nanoparticles

Area of Science:

• Biotechnology
• Nanotechnology
• Marine Biology

Background:

• Selenium is an essential micronutrient with antioxidant and anticancer properties.
• Inorganic selenium is toxic; organic and elemental nanoforms offer better bioavailability and lower toxicity.
• Marine microalgae present a sustainable source for producing selenium nanoparticles (Se-NPs).

Purpose of the Study:

• To optimize the biosynthesis and production of elemental selenium nanoparticles (Se-NPs) using marine microalgae.
• To characterize the synthesized Se-NPs for stability and physical properties.
• To validate the biological functions, specifically antioxidant activity, of the Se-NPs.

Main Methods:

• Biosynthesis of Se-NPs using Nannochloropsis oceanica CASA CC201 algal extract.
• Optimization of precursor concentration and algal extract ratio (10 mM precursor, 1% extract, 10:1 ratio).
• Characterization using Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FT-IR).

Main Results:

• Optimal synthesis conditions yielded highly stable Se-NPs (183 nm size, -38.5 mV zeta potential).
• AFM and TEM confirmed spherical, smooth-surfaced, polydispersely distributed nanoparticles.
• FT-IR analysis indicated microalgae proteins and peptides act as stabilizing and fabricating agents.
• Synthesized elemental nanoform (Se0) demonstrated significant radical scavenging activity (74%).

Conclusions:

• Algal-mediated selenite reduction is an eco-friendly, non-toxic, and sustainable method for Se-NP production.
• The synthesized Se-NPs are highly stable and possess validated biological functions.
• This approach is suitable for large-scale production of Se-NPs for dietary and feed supplements.