Characterisation of selenium and tellurium nanoparticles produced by Aureobasidium pullulans using a multi-method...

Area of Science:

• Environmental Science
• Materials Science
• Biotechnology

Background:

• Biogenic synthesis of metal nanoparticles (NPs) offers sustainable alternatives to chemical methods.
• Selenium (Se) and Tellurium (Te) NPs have potential applications but require robust characterization.
• Aureobasidium pullulans is a known microbial producer of Se and Te NPs.

Purpose of the Study:

• To develop and optimize a method for recovering and characterizing biogenic Se and Te NPs.
• To compare different mobile phases and flow rates for asymmetric flow field-flow fractionation (AF4) separation.
• To investigate the morphology, size, and stability of Se and Te NPs.

Main Methods:

• Biogenic synthesis of Se and Te NPs by Aureobasidium pullulans.
• Separation and characterization using asymmetric flow field-flow fractionation (AF4) coupled with multi-angle light scattering (MALS), UV-Vis spectroscopy, and inductively coupled plasma mass spectrometry (ICP-MS).
• Complementary analysis with transmission electron microscopy (TEM) and dynamic light scattering (DLS).

Main Results:

• Novachem surfactant yielded 88% recovery of Se NPs, superior to phosphate buffer (50%).
• Optimal AF4 conditions (3.5 mL/min crossflow) achieved high recovery rates for both Se (88%) and Te (90%) NPs.
• AF4-MALS indicated monodisperse Se NPs (45-90 nm) and polydisperse Te NPs (5-65 nm). ICP-MS and TEM confirmed particle morphology and size.

Conclusions:

• AF4 coupled with multiple detectors provides a comprehensive platform for characterizing biogenic Se and Te NPs.
• The optimized method using Novachem surfactant enhances NP recovery and stability.
• This study demonstrates the complementary nature of various analytical techniques for understanding biogenic nanomaterials.