State Key Laboratory of Environmental Chemistry and Ecotoxicology , Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , P.O. Box 2871, Beijing 100085 , China.
University of Chinese Academy of Sciences , Beijing 100049 , China.
Anal Chem. 2019 Oct 1;91(19):12525-12530. doi: 10.1021/acs.analchem.9b03359. Epub 2019 Sep 18.
A new method was developed to determine the nanoparticulate and ionic silver (Ag) species in bacteria (, ). By removal of the cell wall with lysozyme, the cell surface-adsorbed Ag species were separated from the intracellular Ag species, which were extracted by tetramethylammonium hydroxide and determined by size-exclusion chromatography coupled with inductively coupled plasma mass spectrometry (SEC-ICP-MS). The detection limit is 3 ng/10 CFU/mL (where CFU is colony-forming unit) for both silver nanoparticles (AgNPs) and ionic Ag(I) species. The cell wall-adsorbed Ag was calculated by subtracting the contents of the intra- and extracellular Ag from the total exposure dose of Ag, and therefore the biodistribution of Ag species was profiled. We then applied this strategy to quantitatively analyze extra- and intracellular Ag species in after respective exposure to Ag and 10 and 30 nm AgNPs at different effective concentrations (EC, EC, and EC). Results showed that the intracellular and cell wall-bound Ag account for 5.98-15.21% and 25.13-64.43% of the exposed dose, respectively, and AgNPs could transform into complexed or free Ag. Our method opens new avenues for the quantitative analysis of the uptake and biodistribution of nanoparticles and their transformation species in bacteria.
开发了一种新方法来测定细菌中的纳米颗粒和离子态银（Ag）物种（，）。通过溶菌酶去除细胞壁，可以将细胞表面吸附的 Ag 物种与细胞内的 Ag 物种分离，然后用四甲基氢氧化铵提取，并通过尺寸排阻色谱与电感耦合等离子体质谱（SEC-ICP-MS）进行测定。对于纳米银颗粒（AgNPs）和离子态 Ag（I），检测限均为 3 ng/10 CFU/mL（其中 CFU 为菌落形成单位）。通过从 Ag 的总暴露剂量中减去细胞内和细胞外 Ag 的含量，可以计算出细胞壁吸附的 Ag，从而可以对 Ag 物种的生物分布进行分析。然后，我们将该策略应用于定量分析 Ag 和 10 和 30 nm AgNPs 在不同有效浓度（EC、EC 和 EC）下暴露后细菌内外细胞中的 Ag 物种。结果表明，细胞内和细胞壁结合的 Ag 分别占暴露剂量的 5.98-15.21%和 25.13-64.43%，并且 AgNPs 可以转化为复合物或游离 Ag。我们的方法为定量分析纳米颗粒及其在细菌中的转化物种的摄取和生物分布开辟了新途径。
