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

Aureobasidium pullulans was grown in liquid culture media amended with selenite and tellurite selenium (Se) tellurium (Te) nanoparticles (NPs) were recovered after 30 d incubation. A separation method applied to recover characterise Se Te NPs by asymmetric flow field fractionation (AF4) online coupling multi-angle light scattering (MALS), ultraviolet visible spectroscopy (UV-Vis), inductively coupled plasma mass spectrometry (ICP-MS) detectors. Additional characterisation data obtained from transmission electron microscopy (TEM), dynamic (DLS). Solutions of 0.2% Novachem surfactant 10 mM phosphate buffer compared as mobile phases investigate optimal AF4 particle recovery using Se-NP a model sample. 88% reported for solution, 50% buffer. Different crossflow (Cflow) rates further optimum separation, recoveries 30% Se-NPs, 90% 29% Te-NPs 3.5 mL min−1 2.5 respectively. Zeta-potential (ZP) suggested higher stability NP elution increased attributed minimised NP-membrane interaction due PEGylation. Detection MALS showed monodisperse Se-NPs (45–90 nm) polydisperse (5–65 nm).Single ICP-MS mean diameters 49.7 ± 2.7 nm, 135 4.3 limit size detection (LOSD) 20 nm 45 TEM images displayed spherical morphology, the showing clustered arrangement, which electrostatic attraction amongst neighbouring particles. Particle hydrodynamic (dH) measured (DLS) distributions, good agreement AF4-MALS but suggests that Rg Te-NP unreliable. The results demonstrate complementary application field-flow (AF4), ICP-MS, scattering, UV-Vis detection, microscopic techniques biogenic NPs.