表面等离子共振传感器用于酒精溶液浓度的测量

采用自行搭建的基于表面等离子共振原理的传感器系统,研究了作为敏感层的不同银膜厚度对表面等离子共振敏感度的影响,并给出了最佳的银膜层厚度.根据表面等离子共振(SPR)现象对金属表面介质折射率极为敏感的特点,在固定波长为632.8 nm的He-Ne激光入射下,利用厚度为50 nm的银薄膜作为敏感层的SPR传感器来测量不同浓度的酒精溶液.通过采用玻尔兹曼方程拟合方法,得出已知酒精溶液的浓度与SPR共振角的关系,从而实现对未知酒精溶液浓度的测量.实验证明测量的浓度分辨率可达0.5%.

Abstract：

Based on surface plasmon resonance (SPR) sensor system, the influence of the Ag-film thickness on the resonance sensitivity was presented. The result shows that the optimal thickness of Ag-film as the sensitive layer of SPR sensor system is about 50 nm. In addition, according to the property that SPR is sensitive to the refractivity of the medium on metal surface, different concentrations of alcohol solution were measured in the experiments at the angular interrogation mode of SPR. The relation between the known concentrations of alcohol solution and its SPR resonance angles was obtained with Boltzmann equation. Consequently, the SPR sensor can be adopt to measure the concentration of alcohol solution and the measuring sensitivity reaches 0.5 %.

Measurement of Concentration of Alcohol Solution with Surface Plasmon Resonance Sensor

Based on surface plasmon resonance (SPR) sensor system, the influence of the Ag-film thickness on the resonance sensitivity was presented. The result shows that the optimal thickness of Ag-film as the sensitive layer of SPR sensor system is about 50 nm. In addition, according to the property that SPR is sensitive to the refractivity of the medium on metal surface, different concentrations of alcohol solution were measured in the experiments at the angular interrogation mode of SPR. The relation between the known concentrations of alcohol solution and its SPR resonance angles was obtained with Boltzmann equation. Consequently, the SPR sensor can be adopt to measure the concentration of alcohol solution and the measuring sensitivity reaches 0.5 %.