基于α-MoO3的可调谐法布里-珀罗谐振腔比色生物传感器

α-MoO3 based tunable Fabry-Pérot cavity colorimetric biosensor

生物传感器是近年来的热点研究方向,其中基于折射率变化的光学传感器在灵敏度方面具有很大优势.本文基于α-MoO3设计了一种集成微流腔的法布里-珀罗谐振腔比色生物传感器.理论分析了BK7/Ag/SiO2作为谐振腔反射面的可行性,并进一步用传输矩阵法分析了所设计的比色生物传感器的透射光谱.当微流腔通过不同浓度的NaCl溶液时,比色生物传感器显示出明显的颜色变化.该比色生物传感器灵敏度最高可达600 nm/RIU,可分辨NaCl溶液9‰的浓度变化.由于α-MoO3具有独特的各向异性的光学性质,该比色传感器可以通过简单的旋转设备实现工作波长的调节以更好地适应人眼的光敏感区.另一方面,调节微流腔的厚度也改变该比色生物传感器的工作波长.该比色生物传感器具有结构简单、易于集成、操作成本低、实时检测等优点,为以后设计可调谐比色传感器提供了一种新的选择.

Biosensor has received increasing attention in recent years due to the demand for detecting biological and chemical substances in liquid.In particular,the detection methods based on refractive index have advantages in detection sensitivity.Colorimetric biosensor can transform the change in refractive index of target into the change in color,which has advantages in simple operation,low cost and real-time detection with naked human eyes.In this work,a Fabry-Perot cavity colorimetric biosensor based on α-MoO3 integrating microfluidic channel is proposed.The α-MoO3 is an emerging natural two-dimensional van der Waals material with anisotropic optical properties due to its unique crystal structure.Theoretical analysis of the feasibility of BK7/Ag/SiO2 as the reflective layers is carried out.And the transmittance spectra of the proposed colorimetric biosensor are calculated by the transfer-matrix method.The obvious color changes can be observed when the microfluidic channel filled with NaCl solutions with different concentrations.The proposed colorimetric biosensor achieves a high detection sensitivity of 600 nm/RIU,which can detect a concentration change of NaCl solution as low as 9‰.The proposed colorimetric biosensor can tune the operating wavelength by simply rotating the device due to the anisotropic optical properties of α-MoO3 to satisfy the color vision of human eyes.Moreover,by tuning the thickness of microfluidic channel,the operating wavelength of colorimetric biosensor can be further shifted.Our approach offers a new direction for developing tunable biosensors with low cost and real-time detection.