Rigamonti Giulia, Guardamagna Marco, Bello Valentina, Marconi Stefania, Auricchio Ferdinando, Merlo Sabina
Dipartimento di Ingegneria Industriale e dell'Informazione, University of Pavia, 27100, Pavia, Italy.
Dipartimento di Ingegneria Civile e Architettura, University of Pavia, 27100, Pavia, Italy.
Biomed Opt Express. 2017 Sep 11;8(10):4438-4453. doi: 10.1364/BOE.8.004438. eCollection 2017 Oct 1.
We present a flow-through refractive index sensor for measuring the concentration of glucose solutions based on the application of rectangular glass micro-capillaries, with channel depth of 50 µm and 30 µm. A custom designed and 3D printed polymeric shell protects the tiny capillaries, ensuring an easier handling and interconnection with the macro-fluidic path. By illuminating the capillary with broadband radiation centered at λ~1.55 µm, both the transmitted (T) and reflected (R) optical spectrum from the capillary are detected with an optical spectrum analyzer, exploiting an all-fiber setup. Monitoring the spectral shift of the ratio T/R in response to increasing concentration of glucose solutions in water we have obtained sensitivities up to 530.9 nm/RIU and limit of detection in the range of 10-10 RIU. Experimental results are in agreement with the theoretically predicted principle of operation. After the demonstration of amplitude detection at a single wavelength, we finally discuss the impact of the capillary parameters on the sensitivity.
我们展示了一种基于矩形玻璃微毛细管应用的流通式折射率传感器，用于测量葡萄糖溶液的浓度，其通道深度分别为50 µm和30 µm。定制设计并通过3D打印的聚合物外壳保护这些微小的毛细管，确保更易于操作并与宏观流体路径互连。通过用中心波长为λ~1.55 µm的宽带辐射照射毛细管，利用全光纤装置，用光谱分析仪检测来自毛细管的透射（T）光谱和反射（R）光谱。监测T/R比值随水中葡萄糖溶液浓度增加的光谱偏移，我们获得了高达530.9 nm/RIU的灵敏度和10-10 RIU范围内的检测限。实验结果与理论预测的操作原理一致。在演示了单波长幅度检测后，我们最后讨论了毛细管参数对灵敏度的影响。
