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.%Nanoporous gold films (NPGFs) are chemically robust and thermally stable,have large specific area and salient surface plasmon resonance (SPR) effect.Due to these features,NPGFs are quite applicable for high-sensitivity SPR sensors.In this study,the SPR effect of NPGFs was theoretically analyzed and the dispersion relation was obtained for propagating surface plasmons at the NPGF/air interface.The optimal thickness of NPGF required for optimizing its SPR sensing performance was determined to be ～60 nm.Large-area,uniform and ultrathin NPGFs were prepared by a two-step approach involving sputtering deposition and chemical dealloying.The SPR resonance band in the visible-near-infrared region and the sensing properties of NPGFs were measured with the Kretschmann prism-coupling configuration.Porosity of the NPGF was determined to be ～0.38 by fitting the measured resonance wavelengths based on a 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) in water,the NPGF-SPR sensor can easily detect BPA at concentrations as low as 5 nmol.L1.After hydrophobilization of NPGFs,the sensor enables detection of trace amounts of benzo[a]pyrene (BaP) in water,with the detection limit being 1 nmol·L-1.
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