Guijarro-Ramírez Nuria, Sáez-Zamacona Iraide, Torregrosa Daniel, Grindlay Guillermo, Gras Luis, Pire Carmen, Mora Juan, Martínez-Espinosa Rosa María
Department of Analytical Chemistry, Nutrition, and Food Sciences, PO Box 99, 03080, Alicante, University of Alicante, Spain; Multidisciplinary Institute for Environmental Studies "Ramón Margalef", University of Alicante, Ap. 99, E-03080, Alicante, Spain.
Multidisciplinary Institute for Environmental Studies "Ramón Margalef", University of Alicante, Ap. 99, E-03080, Alicante, Spain; Biochemistry, Molecular Biology, Edaphology and Agricultural Chemistry Department, Faculty of Sciences, University of Alicante, Ap. 99, E-03080 Alicante, Spain.
Anal Chim Acta. 2025 Jan 15;1335:343453. doi: 10.1016/j.aca.2024.343453. Epub 2024 Nov 21.
Single particle inductively coupled plasma mass spectrometry (spICP-MS) is extensively employed for the characterization of biogenic selenium nanoparticles (SeNPs) produced by mesophilic microorganisms. Nevertheless, because halophilic microorganisms are also well-known to produce SeNPs, further research efforts are required to investigate spICP-MS applicability for characterizing such nanomaterials in hypersaline media. The goal of this work is to develop a methodology for characterizing SeNPs in hypersaline media by spICP-MS. To this end, plasma operating conditions, non-spectral interferences and calibration strategies were investigated. The proposed method was employed to investigate the capabilities of the halophilic archaea Haloferax mediterranei to produce SeNPs.
By the appropriate selection of experimental conditions, SeNPs can be accurately analyzed in hypersaline media by spICP-MS. Unlike previous works in the literature, no differences in ionic signal were observed between SeNPs and dissolved Se and, hence, there is no need to apply any empirical corrector factor for obtaining accurate particle size distributions. Non-spectral interferences are mitigated by diluting the sample at least 1:10 which allows the use of water standards. Size (30 nm) and particle (7 × 10 particles mL) detection limits were low enough to characterize biogenic SeNPs produced by halophilic microorganisms. The use of the optimized methodology reveals that Haloferax mediterranei can produce SeNPs when it is exposed to selenite up to 1 mM, but no formation is produced for selenate exposure. Depending on incubation parameters (selenite concentration and time), the particle median diameter ranged from 80 to 100 nm, whereas particle concentration varied from 0.8 to 1.9 × 10 particles mL.
This represents the first methodology for characterizing biogenic SeNPs in hypersaline media by spICP-MS with accuracy and precision using non-matrix matched standards. It opens the opportunity to investigate the capabilities of halophilic microorganisms (e.g., H. mediterranei) to produce Se-based nanomaterials.
单颗粒电感耦合等离子体质谱法（spICP-MS）被广泛用于表征嗜温微生物产生的生物源硒纳米颗粒（SeNPs）。然而，由于已知嗜盐微生物也能产生SeNPs，因此需要进一步研究spICP-MS在高盐介质中表征此类纳米材料的适用性。本工作的目标是开发一种通过spICP-MS在高盐介质中表征SeNPs的方法。为此，研究了等离子体操作条件、非光谱干扰和校准策略。所提出的方法用于研究嗜盐古菌地中海嗜盐嗜热栖热放线菌产生SeNPs的能力。
通过适当选择实验条件，spICP-MS可以在高盐介质中准确分析SeNPs。与文献中先前的工作不同，在SeNPs和溶解态硒之间未观察到离子信号差异，因此无需应用任何经验校正因子来获得准确的粒径分布。通过将样品至少按1:10稀释可减轻非光谱干扰，这允许使用水标准物质。尺寸（30 nm）和颗粒（7×10颗粒/mL）检测限足够低，能够表征嗜盐微生物产生的生物源SeNPs。使用优化方法表明，地中海嗜盐嗜热栖热放线菌在暴露于高达1 mM的亚硒酸盐时可以产生SeNPs，但暴露于硒酸盐时不产生SeNPs。根据培养参数（亚硒酸盐浓度和时间），颗粒中位直径范围为80至100 nm，而颗粒浓度在0.8至1.9×10颗粒/mL之间变化。
这代表了第一种通过spICP-MS使用非基质匹配标准准确、精确地表征高盐介质中生物源SeNPs的方法。它为研究嗜盐微生物（如地中海嗜盐嗜热栖热放线菌）产生硒基纳米材料的能力提供了机会。
