National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donath, 400293 Cluj-Napoca, Romania.
Biomolecular Physics Department, Babeş-Bolyai University, Kogălniceanu 1, 400084 Cluj Napoca, Romania.
Biosensors (Basel). 2023 Dec 29;14(1):19. doi: 10.3390/bios14010019.
Water samples from two naturally hypersaline lakes, renowned for their balneotherapeutic properties, were investigated through a pilot SERS monitoring program. Nanotechnology-based techniques were employed to periodically measure the ultra-sensitive SERS molecular characteristics of the raw water-bearing microbial community and the inorganic content. Employing the Pearson correlation coefficient revealed a robust linear relationship between electrical conductivity and pH and Raman and SERS spectral data of water samples, highlighting the interplay complexity of Raman/SERS signals and physicochemical parameters within each lake. The SERS data obtained from raw waters with AgNPs exhibited a dominant, reproducible SERS feature resembling adsorbed β-carotene at submicromole concentration, which could be related to the cyanobacteria-AgNPs interface and supported by TEM analyses. Notably, spurious SERS sampling cases showed molecular traces attributed to additional metabolites, suggesting multiplexed SERS signatures. The conducted PCA demonstrated observable differences in the β-carotene SERS band intensities between the two lakes, signifying potential variations in picoplankton abundance and composition or environmental influences. Moreover, the study examined variations in the SERS intensity ratio I/I, related to the balance between inorganic (Cl-induced AgNPs aggregation) and organic (cyanobacteria population) balance, in correlation with the electrical conductivity. These findings signify the potential of SERS data for monitoring variations in microorganism concentration, clearly dependent on ion concentration and nutrient dynamics in raw, hypersaline water bodies.
通过一项试点 SERS 监测计划，对两个以其浴疗特性而闻名的天然高盐湖泊的水样进行了研究。采用基于纳米技术的技术定期测量原始含水微生物群落和无机成分的超灵敏 SERS 分子特征。运用皮尔逊相关系数揭示了电导率和 pH 值与拉曼和 SERS 光谱数据之间的稳健线性关系，突出了拉曼/SERS 信号与每个湖泊内理化参数之间的相互作用复杂性。在含有 AgNPs 的原水中获得的 SERS 数据表现出主导的、可重现的 SERS 特征，类似于亚毫摩尔浓度下吸附的β-胡萝卜素，这可能与蓝藻-AgNPs 界面有关，并得到 TEM 分析的支持。值得注意的是，虚假的 SERS 采样情况显示出归因于其他代谢物的分子痕迹，表明存在多重 SERS 特征。进行的 PCA 表明，两个湖泊之间的β-胡萝卜素 SERS 带强度存在可观察到的差异，表明微微型浮游生物丰度和组成或环境影响可能存在差异。此外，该研究还检查了与电导率相关的 I/I 比值（与无机（Cl 诱导的 AgNPs 聚集）和有机（蓝藻种群）平衡之间的平衡有关）的 SERS 强度比的变化。这些发现表明 SERS 数据具有监测微生物浓度变化的潜力，而微生物浓度明显取决于原始高盐水体中的离子浓度和营养动态。
