Department of Physical and Inorganic Chemistry, Universitat Rovira i Virgili, Carrer de Marcel lí Domingo s/n, 43007 Tarragona, Spain.
Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08010 Barcelona, Spain.
Biosensors (Basel). 2022 Apr 22;12(5):267. doi: 10.3390/bios12050267.
Low molecular weight thiols (biothiols) are highly active compounds extensively involved in human physiology. Their abnormal levels have been associated with multiple diseases. In recent years, major efforts have been devoted to developing new nanosensing methods for the low cost and fast quantification of this class of analytes in minimally pre-treated samples. Herein, we present a novel strategy for engineering a highly efficient surface-enhanced Raman scattering (SERS) spectroscopy platform for the dynamic sensing of biothiols. Colloidally stable silver nanoparticles clusters equipped with a specifically designed azobenzene derivative (AzoProbe) were generated as highly SERS active substrates. In the presence of small biothiols (e.g., glutathione, GSH), breakage of the AzoProbe diazo bond causes drastic spectral changes that can be quantitatively correlated with the biothiol content with a limit of detection of ca. 5 nM for GSH. An identical response was observed for other low molecular weight thiols, while larger macromolecules with free thiol groups (e.g., bovine serum albumin) do not produce distinguishable spectral alterations. This indicates the suitability of the SERS sensing platform for the selective quantification of small biothiols.
低分子量硫醇（生物硫醇）是一种高度活跃的化合物，广泛参与人体生理学。它们的异常水平与多种疾病有关。近年来，人们致力于开发新的纳米传感方法，以低成本和快速定量分析最小预处理样品中的这类分析物。在此，我们提出了一种用于生物硫醇动态传感的高效表面增强拉曼散射（SERS）光谱平台的新型构建策略。胶体稳定的银纳米粒子簇配备了专门设计的重氮苯衍生物（AzoProbe），作为高度 SERS 活性基底。在小分子生物硫醇（如谷胱甘肽，GSH）存在下，AzoProbe 的重氮键断裂会导致光谱发生剧烈变化，可与生物硫醇含量定量相关，GSH 的检测限约为 5 nM。其他低分子量硫醇也观察到了相同的响应，而具有游离巯基的较大的大分子（如牛血清白蛋白）不会产生可区分的光谱变化。这表明 SERS 传感平台适用于小分子生物硫醇的选择性定量。
