基于光导毛细管器件的SPR生物传感器及IgG检测

SPR biosensor based on light guiding capillary element and IgG detection

光纤表面等离子体共振（surface plasmon resonance,SPR）传感技术具有免标记、灵敏度高、体积小、成本低等优点.在传统的光纤 SPR 传感器件基础上设计制造了光导毛细管SPR 传感器件,利用自行研制的波长调制式 SPR 传感装置,对器件灵敏度、分辨率和检测精密度等方面的性能进行了评价.相比光纤 SPR 传感器件,光导毛细管 SPR 传感器件产生更显著的 SPR 效应,提高系统分辨率达9.6×10-6 RIU（折射率单位）.应用光导毛细管 SPR 传感器件可进行 IgG 快速、定量检测,检测线性范围受传感区固定的蛋白 A 疏密程度影响,其中0.01 mg/mL 蛋白 A 修饰条件下检测线性范围是0.33~1.53μmol/L,0.10 mg/mL 蛋白A 修饰条件下检测线性范围是0.20~3.67μmol/L；并进行了蛋白 A-IgG 的解离常数测定, Kd=1.4×10-7 mol/L.相对于现有商业 SPR 仪器,基于光导毛细管器件的 SPR 生物传感器使用成本低、便携性好,具有良好的应用前景.

Fiber-optic surface plasmon resonance （SPR）sensing technology has the advantages of label-free,high sensitivity,miniaturization and low cost,etc..The light guiding capillary SPR sensing element was fabricated on the basis of the fiber-optic SPR sensing element.Using the home-built wavelength-modulated SPR sensing apparatus,their sensitivity,resolution and precision of detection were evaluated.Compared with the fiber-optic SPR sensing element,the light guiding capillary SPR sensing element generates a stronger SPR effect and improves the system resolution （9.6×10 -6 refractive index unit）.Using the light guiding capillary SPR sensing element to detect IgG could achieve rapid and quantitative detection.The linear detection range of IgG is affected by the density of protein A immobilized on the sensing area,and under 0.01 mg/mL protein A modified condition is 0.33-1.53 μmol/L,under 0.10 mg/mL protein A modified condition is 0.20-3.67 μmol/L.Moreover,the dissociation constant of protein A and IgG could be obtained （K d =1.4×10 -7 mol/L）.Compared with existing commercial SPR instruments,the low-cost and portable SPR biosensor based on the light guiding capillary element has good prospects.