Golden J P, Anderson G P, Rabbany S Y, Ligler F S
Center for Bio/Molecular Science and Engineering, Naval Research Laboratory Washington, DC 20375-5348.
IEEE Trans Biomed Eng. 1994 Jun;41(6):585-91. doi: 10.1109/10.293246.
A biosensor was developed using antibodies, fluorescence and the evanescent wave to detect antigen binding at the surface of an optical fiber. Cladding was removed from the core along the distal end of a step-index optical fiber, and recognition antibodies were immobilized on the declad core to form the probe sensing region. Immersing the declad probe in aqueous solution creates a V-number mismatch between the immersed probe and the clad fiber. Probes created with reduced sensing region radius exhibited improved response by decreasing the V-number mismatch. Tapering the radius of this region has further improved probe response. Ray tracing analysis of the tapered probe demonstrated that the evanescent wave penetration depth increases along the length of the taper. Experiments correlating position of refraction along the taper with launch angle at the proximal end were realized in the ray tracing model. An evanescent wave immunoassay was performed with a series of the tapered fiber probes, each tapered from the fiber core radius (100 microns) to different end radii. An end radius of 29 microns was found to produce maximal signal from the tapered probe. Factors leading to the determination of the optimized probe are discussed.
一种利用抗体、荧光和倏逝波开发的生物传感器，用于检测光纤表面的抗原结合。沿着阶跃折射率光纤的远端从纤芯去除包层，并将识别抗体固定在去包层的纤芯上以形成探针传感区域。将去包层的探针浸入水溶液中会在浸入的探针和包层光纤之间产生V值失配。通过减小V值失配，减小传感区域半径制成的探针表现出更好的响应。使该区域的半径逐渐变细进一步改善了探针响应。对锥形探针的光线追踪分析表明，倏逝波穿透深度沿锥形长度增加。在光线追踪模型中实现了将沿锥形的折射位置与近端的发射角相关联的实验。用一系列锥形光纤探针进行了倏逝波免疫测定，每个探针从光纤纤芯半径（100微米）逐渐变细到不同的末端半径。发现29微米的末端半径可使锥形探针产生最大信号。讨论了导致确定优化探针的因素。
