Kim Il Tai, Kihm Kenneth D
Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville, Tennessee 37996-2210, USA.
Anal Chem. 2007 Jul 15;79(14):5418-23. doi: 10.1021/ac070301s. Epub 2007 Jun 13.
An idea of real-time and full-field detection of near-wall salinity is presented to use the surface plasmon resonance (SPR) reflectance that changes with refractive index variations of the tested saline fluid. The laboratory-designed SPR system, based on the Kretschmann's configuration, uses a 47.5 nm thick gold layer as the SPR resonator, coated on a BK7 prism (n=1.515), and requires a one-time system calibration to establish a correlation of the specified saline mass concentration levels to the corresponding CCD (charge-coupled device) pixel gray levels. As a gravity-falling saline drop in water reaches the bottom and diffuses thereafter, the SPR system quantitatively maps the evolution of the salinity distributions in the near-wall region (less than 1 microm). An elaborate uncertainty analysis shows that the overall measurement uncertainties critically depend on the uniformity of the metal film thickness and the accuracy of its dielectric constant.
提出了一种利用随被测盐水流体折射率变化而改变的表面等离子体共振（SPR）反射率对近壁盐度进行实时全场检测的方法。基于Kretschmann结构在实验室设计的SPR系统，使用厚度为47.5nm的金层作为SPR谐振器，涂覆在BK7棱镜（n = 1.515）上，并且需要进行一次系统校准，以建立特定盐质量浓度水平与相应电荷耦合器件（CCD）像素灰度级之间的相关性。当水中重力下落的盐滴到达底部并随后扩散时，SPR系统定量地描绘了近壁区域（小于1微米）盐度分布的演变。详尽的不确定度分析表明，总体测量不确定度主要取决于金属膜厚度的均匀性及其介电常数的准确性。
