基子全内反射萤光原理的免疫传感器

AN IMMUNOSENSOR BASED ON TIRF PRINCIPLE

本文描述了一种以全内反射荧光(TIRF)原理为基础的平面光波导免疫传感器。由于光波导表面消失波具有空间分隔效应,传感器可在不干扰测试溶液的情况下监测器件表面的免疫反应。本文通过对特异性、非特异性及散射信号的测量,研究了非特异性吸附对传感器性能的影响及表面膜的特异性结合能力。通过选择合适的再生条件,传感器在使用数次后性能未见明显的改变。最后文章给出了传感器的检测灵敏度及检测范围。

<ABSTRACT> Based upon TIRF principle, an immunosensor for monitoring antibod- y-antigen reactions at the solution-ouartz interface was developed. The antigen (human-IgG ) was covalently attached to the surface of a planar quartz waveguide. When the light beam passes through the waveguide, only the FITC labeled autibody primarily bound (or very close ) to the surface was excited by the evanescent wave on the surface,which resulted in apatial seperation of the bound Ag-Ab compounds from the free mol- ccules in the bulk. In this poper, the non-bindingsignal. non-specifie and specific binding signals were measured respectively,and the immuno- competitive assay described, showing of the dynamic detecting range capable of being adjusted. When the concentration of competitive rea- gent was 50μg/ml, detecting limit of the sensor was approximately lμg/ ml. But for direct immumoassay of labeled antibody, the sensitivity was about 0.5μg/ml. The recycle of solid phase protein showed no obvious loss of biological activity after use of 8 times. It is expected that this immunosensor sbould have wide applicability in both routine and resea- rcb field.