环境温度的变化对表面等离子体共振(SPR)检测系统产生的热效应会影响共振条件和相关输出量。建立液体棱镜SPR检测系统,对系统中各介质层的热性能进行详细分析。基于介质层的折射率与温度关系的理论模型,数值模拟了环境温度变化对各介质层共振曲线和共振角的影响。模拟结果表明去离子水的热致折射率变化比玻璃基底和金属薄膜高1~2个数量级。实验上,采用自主搭建的共振检测系统研究共振角偏移和水的折射率变化对外界温度改变的依赖关系。结果表明当外界环境温度变化范围为29 K时,共振角偏移量是0.216°,水的折射率变化达到4.02×10 ^-3,并推导出水的折射率与温度之间关系的表达式。实验结果和理论计算基本一致,为进一步提高检测系统的灵敏度奠定了基础。

It is demonstrated that, in the surface plasmon resonance (SPR) detection system, the thermal effect generated by the variation of environmental temperature will affect the resonance condition and correlated output. The SPR detection system based on the liquid prism is set up, in which the thermal performance of each dielectric layer is analyzed in detail. Based on the theoretical model on the relationship between the refractive index of the dielectric layer and the temperature, the influences of the environment temperature variation on both the resonance curve and resonance angle of each dielectric layer are numerically simulated. The simulated results show that the thermal effected refraction variation of deionized water are 1-2 orders higher than that of glass substrate and metal film. By exploiting self-build resonance detection system, we experimentally explore the dependences of both the resonance angle deviation and the refractive index change of water on environmental temperature variation. The results indicate that when the variation range of the environment temperature is 29 K, the resonance angle offset is 0.216° and the refraction change of the water reaches up to 4.02×10 -3. Also, the formula of the relationship between the refraction of the water and the temperature is attained. The experimental results basically agree with the theoretical calculations, which lay foundation for further improvement of the sensitivity of the detection system.