Trace Element Speciation Laboratories, Dept. of Chemistry, University of Aberdeen, AB24 3UE, United Kingdom.
Geomicrobiology Group, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom.
J Chromatogr A. 2021 Apr 12;1642:462022. doi: 10.1016/j.chroma.2021.462022. Epub 2021 Feb 27.
Aureobasidium pullulans was grown in liquid culture media amended with selenite and tellurite and selenium (Se) and tellurium (Te) nanoparticles (NPs) were recovered after 30 d incubation. A separation method was applied to recover and characterise Se and Te NPs by asymmetric flow field flow fractionation (AF4) with online coupling to multi-angle light scattering (MALS), ultraviolet visible spectroscopy (UV-Vis), and inductively coupled plasma mass spectrometry (ICP-MS) detectors. Additional characterisation data was obtained from transmission electron microscopy (TEM), and dynamic light scattering (DLS). Solutions of 0.2% Novachem surfactant and 10 mM phosphate buffer were compared as mobile phases to investigate optimal AF4 separation and particle recovery using Se-NP as a model sample. 88% recovery was reported for 0.2% Novachem solution, compared with 50% recovery for phosphate buffer. Different crossflow (C) rates were compared to further investigate optimum separation, with recoveries of 88% and 30% for Se-NPs, and 90% and 29% for Te-NPs for 3.5 mL min and 2.5 mL min respectively. Zeta-potential (ZP) data suggested higher stability for NP elution in Novachem solution, with increased stability attributed to minimised NP-membrane interaction due to PEGylation. Detection with MALS showed monodisperse Se-NPs (45-90 nm) and polydisperse Te-NPs (5-65 nm).Single particle ICP-MS showed mean particle diameters of 49.7 ± 2.7 nm, and 135 ± 4.3 nm, and limit of size detection (LOSD) of 20 nm and 45 nm for Se-NPs and Te-NPs respectively. TEM images of Se-NPs and Te-NPs displayed a spherical morphology, with the Te-NPs showing a clustered arrangement, which suggested electrostatic attraction amongst neighbouring particles. Particle hydrodynamic diameters (d) measured with dynamic light scattering (DLS) further suggested monodisperse Se-NPs and polydisperse Te-NPs distributions, showing good agreement with AF4-MALS for Se-NPs, but suggests that the R obtained from AF4-MALS for Te-NP was unreliable. The results demonstrate a complementary application of asymmetric flow field-flow fractionation (AF4), ICP-MS, light scattering, UV-Vis detection, and microscopic techniques to characterise biogenic Se and Te NPs.
在添加亚硒酸钠和碲酸钠的液体培养基中培养出出泡被毛霉（ Aureobasidium pullulans ），经过 30 天的培养后回收硒（ Se ）和碲（ Te ）纳米颗粒（ NPs ）。采用不对称流场流分离（ AF4 ）方法，并在线耦合多角度光散射（ MALS ）、紫外可见分光光度法（ UV-Vis ）和电感耦合等离子体质谱法（ ICP-MS ）检测器，对 Se 和 Te NPs 进行分离和表征。通过透射电子显微镜（ TEM ）和动态光散射（ DLS ）获得了更多的特征数据。将 0.2%Novachem 表面活性剂和 10mM 磷酸盐缓冲液的溶液作为流动相进行比较，以研究使用 Se-NP 作为模型样品的最佳 AF4 分离和颗粒回收。对于 0.2%Novachem 溶液，报告的回收率为 88%，而对于磷酸盐缓冲液，回收率为 50%。为了进一步研究最佳分离，比较了不同的交叉流（ C ）速率，对于 Se-NPs 的回收率为 88%和 30%，对于 Te-NPs 的回收率为 90%和 29%，分别为 3.5mL min 和 2.5mL min 。Zeta 电位（ ZP ）数据表明，NP 在 Novachem 溶液中的洗脱稳定性更高，由于 PEG 化，NP-膜相互作用最小化，因此稳定性增加。MALS 的检测表明，Se-NPs （ 45-90nm ）呈单分散性，Te-NPs （ 5-65nm ）呈多分散性。单颗粒 ICP-MS 显示 49.7±2.7nm 的平均粒径和 Se-NPs 的 LOSD 为 20nm ， Te-NPs 的 LOSD 为 45nm 。Se-NPs 和 Te-NPs 的 TEM 图像显示出球形形态，Te-NPs 显示出聚集排列，这表明相邻颗粒之间存在静电吸引力。动态光散射（ DLS ）测量的颗粒水动力直径（ d ）进一步表明，Se-NPs 呈单分散性，Te-NPs 呈多分散性，与 AF4-MALS 对 Se-NPs 的结果吻合较好，但表明 AF4-MALS 对 Te-NP 获得的 R 值不可靠。结果表明，不对称流场流分离（ AF4 ）、ICP-MS 、光散射、紫外可见检测和显微镜技术可互补应用于生物合成的 Se 和 Te NPs 的表征。
