School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, P.R. China; Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, College of Chemistry and Materials Science, South Central University for Nationalities, Wuhan 430074, P.R. China.
School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, P.R. China.
Anal Chim Acta. 2014 Mar 13;816:41-9. doi: 10.1016/j.aca.2014.01.046. Epub 2014 Feb 3.
Unsatisfactory sensitivity and stability for molecules with low polarizability is still a problem limiting the practical applications of surface-enhanced Raman scattering (SERS) technique. By preparing immobilized silver nanoparticles (Fe3O4/Ag) through depositing silver on the surface of magnetite particles, a highly sensitive and selective SERS method for the detection of trace glutathione (GSH) was proposed on the basis of a system of Fe3O4/Ag nanoparticles and crystal violet (CV), in which the target GSH competed with the CV probe for the adsorption on the Fe3O4/Ag nanoparticles. Raman insensitive GSH replaced the highly Raman sensitive CV adsorbed on the surface of Fe3O4/Ag particles. This replacement led to a strong decrease of the CV SERS signal, which was used to determine the concentration of GSH. Under optimal conditions, a linear response was established between the intensity decrease of the CV SERS signal and the GSH concentration in the range of 50-700 nmol L(-1) with a detection limit of 40 nmol L(-1). The use of a Fe3O4/Ag substrate provided not only a great SERS enhancement but also a good stability, which guarantees the reproducibility of the proposed method. Its use for the determination of GSH in practical blood samples and cell extract yielded satisfactory results.
对于低极化率分子，灵敏度和稳定性不理想仍然是限制表面增强拉曼散射（SERS）技术实际应用的一个问题。通过在磁铁矿颗粒表面沉积银来制备固定化银纳米颗粒（Fe3O4/Ag），基于 Fe3O4/Ag 纳米颗粒和结晶紫（CV）的体系，提出了一种用于痕量谷胱甘肽（GSH）检测的高灵敏度和选择性 SERS 方法，其中目标 GSH 与 CV 探针竞争吸附在 Fe3O4/Ag 纳米颗粒上。拉曼不灵敏的 GSH 取代了吸附在 Fe3O4/Ag 颗粒表面的高拉曼灵敏的 CV。这种取代导致 CV SERS 信号的强烈下降，该信号用于确定 GSH 的浓度。在最佳条件下，CV SERS 信号强度的降低与 50-700nmol L(-1)范围内的 GSH 浓度之间建立了线性响应，检测限为 40nmol L(-1)。使用 Fe3O4/Ag 基底不仅提供了很大的 SERS 增强，而且还具有很好的稳定性，保证了所提出方法的重现性。它用于实际血液样本和细胞提取物中 GSH 的测定，得到了令人满意的结果。
