基于NIR-SERS基底的柠檬酸钠、氯化血红素NIR-SERS光谱研究

NIR-SERS Studies of Sodium Citrate and Chloride Hematin Based on NIR-SERS Substrate

本文采用电解法结合静电自组装技术制得了二维纳米银膜,该纳米银膜的UV-vis消光光谱显示其等离子体共振带位于400 nm^900 nm之间,延伸至近红外区。该纳米银膜可以较好的匹配785 nm的近红外激发光源,进而能有效的避免分子荧光和生物分子的光致损伤。本文以柠檬酸钠和氯化血红素为探测分子,进行了近红外表面增强拉曼散射(NIR-SERS)活性检测,获得了信噪比较好的NIR-SERS光谱图。同时采用密度泛函理论B3LYP,以6-31G为基函数,对柠檬酸钠分子进行了结构优化和普通拉曼光谱(NR)计算,发现理论值和实验值符合很好。此外,文中对柠檬酸钠及氯化血红素的NIR-SERS谱带进行了分析和归属。实验表明,该二维纳米银膜是一种稳定、高效且具有生物兼容性的NIR-SERS基底,与近红外激发光源相匹配可以有效的淬灭分子荧光、增强拉曼信号。

Two-dimensional Ag films were obtained by using the method of electrostatic self-assembly in this paper. UV-vis extinction data shown that the plasmonic resonance band of this Ag film was in the region of 400nm-900 nm, and extended to the near-infrared region. It was found that, this extinction characteristic worked well with the near-infrared laser source （785 nm） employed in our work,which is able to avoid the molecule fluorescence and biological macromolecules degradation. By using the test molecules of sodium citrate and chloride hematin, NIR-SERS activitis of the Ag film were performed in this paper. Meanwhile, geometry optimization and wavenumber calculations of sodium citrate were performed by using the method of DFT-B3LYP/6-31G, and found that the experi- mental data matched well with the calculational values. On the other hand, the assigna-tions of the NIR-SERS bands of sodium citrate and chloride hematin were performed in this work. The experimental results show that, the Ag films obtained electrostatic self-assembly are active, stable and biocompatible NIR-SERS substrate.