物理化学学报 >> 2017, Vol. 33 >> Issue (6): 1223-1229.doi: 10.3866/PKU.WHXB201702282

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纳米多孔金膜表面等离子体共振效应的理论分析和传感应用

王丽1,2,逯丹凤1,高然1,程进1,张喆3,祁志美1,*()   

  1. 1 中国科学院电子学研究所,传感技术国家重点实验室,北京100190
    2 中国科学院大学,北京100049
    3 北京交通大学计算机与信息技术学院,北京100044
  • 收稿日期:2016-12-15 发布日期:2017-05-19
  • 通讯作者: 祁志美 E-mail:zhimei-qi@mail.ie.ac.cn
  • 基金资助:
    国家重点基础研究发展规划项目(973)(2015CB352100);国家自然科学基金(61377064);国家自然科学基金(61401432);国家自然科学基金(61401019);国家自然科学基金(61675203);中国科学院科研装备研制项目(YZ201508)

Theoretical Analyses and Chemical Sensing Application of Surface Plasmon Resonance Effect of Nanoporous Gold Films

Li WANG1,2,Dan-Feng LU1,Ran GAO1,Jin CHENG1,Zhe ZHANG3,Zhi-Mei QI1,*()   

  1. 1 State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
    2 University of Chinese Academy of Sciences, Beijing 100049, P. R. China
    3 Beijing Jiaotong University, School of Computer and Information Technology, Beijing 100044, P. R. China
  • Received:2016-12-15 Published:2017-05-19
  • Contact: Zhi-Mei QI E-mail:zhimei-qi@mail.ie.ac.cn
  • Supported by:
    the National Key Basic Research Program of China (973)(2015CB352100);National Natural Science Foundation of China(61377064);National Natural Science Foundation of China(61401432);National Natural Science Foundation of China(61401019);National Natural Science Foundation of China(61675203);Research Equipment Development Project of Chinese Academy of Sciences(YZ201508)

摘要:

纳米多孔金膜(NPGF)化学和热力学稳定性好,比表面积大,具有显著的表面等离子体共振(SPR)效应,适宜于用作SPR生化传感芯片。本文对NPGF的SPR效应进行了理论分析,得到了在NPGF/空气界面传播的表面等离子体色散曲线,获得了优化NPGF-SPR传感性能所需的最佳薄膜厚度约为60 nm;在此基础上利用溅射沉积-化学脱合金两步法在玻璃基板上制备出大面积均匀的超薄NPGF,采用Krestchmann棱镜耦合结构测试了NPGF在可见-近红外波段的SPR共振光谱及其传感特性,通过利用菲涅耳公式并结合Bruggeman介电常数近似理论对测得的共振波长进行拟合,得出NPGF的孔隙率约为0.38。未经修饰的NPGF是亲水薄膜,能够有效富集水中的双酚A,使得NPGF-SPR传感器对双酚A的探测下限达到5 nmol·L-1;经过疏水化处理后,NPGF对非极性苯并芘分子的富集能力获得显著增强,使得传感器对苯并芘的探测下限达到1 nmol·L-1

关键词: 纳米多孔金膜, 传播表面等离子体共振, 富集, 高灵敏度, 苯并芘

Abstract:

Nanoporous gold films (NPGFs) are chemically robust and thermally stable, possessing large specific area and salient surface plasmon resonance (SPR) effect. With these features NPGFs are quite applicable for high-sensitivity SPR sensors. In this work, the SPR effect of NPGFs was theoretically analyzed and the dispersion relation of propagating surface plasmons at the NPGF/air interface was obtained. The optimal thickness of NPGF required for optimizing its SPR sensing performance was achieved to be about 60 nm. Large-area, uniform and ultrathin NPGFs were prepared by a two-step approach consisting of sputtering deposition and chemical dealloying. The SPR resonance band in the visible-near-infrared region and the sensing properties of NPGF were measured with the Kretschmann prism-coupling configuration. Porosity of the NPGF is determined to be about 0.38 by fitting the measured resonance wavelengths based on the combination of the Fresnel formula and the Bruggeman dielectric constant approximation theory. Since the non-modified NPGFs are hydrophilic and enable effective enrichment of bisphenol A (BPA) molecules in water, the NPGF-SPR sensor can easily detect BPA with concentrations as low as 5 nmol·L-1. After hydrophobilization of NPGFs, the sensor enables detection of trace benzo[a]pyrene (BaP) in water, with the detection limit of 1 nmol·L-1.

Key words: Nanoporous gold film, Propagating surface plasmon resonance, Enrichment, High sensitivity, Benzo[a]pyrene

MSC2000: 

  • O647