Abstract：
A novel fiber optic biosensor was purposed for a new approach to monitor amyloid beta protein fragment 1-42 (Aβ42) for Alzheimer\'s Disease (AD) early detection. The sensor was fabricated by etching a part of fiber from single mode fiber loop in pure hydrofluoric acid solution and utilized as a Local Optical Refractometer (LOR) to monitor the change Aβ42 concentration in Artificial Cerebrospinal Fluid (ACSF). The Fiber Loop Ringdown Spectroscopy (FLRDS) technique is an ultra-sensitive measurement technique with low-cost, high sensitivity, real-time measurement, continuous measurement and portability features that was utilized with a fiber optic sensor for the first time for the detection of a biological signature in an ACSF environment. Here, the measurement is based on the total optical loss detection when specially fabricated sensor heads were immersed into ACSF solutions with and without different concentrations of Aβ42 biomarkers since the bulk refractive index change was performed. Baseline stability and the reference ring down times of the sensor head were measured in the air as 0.87% and 441.6μs ± 3.9μs, respectively. Afterward, the total optical loss of the system was measured when the sensor head was immersed in deionized water, ACSF solution, and ACSF solutions with Aβ42 in different concentrations. The lowest Aβ42 concentration of 2 ppm was detected by LOR. Results showed that LOR fabricated by single-mode fibers for FLRDS system design are promising candidates to be utilized as fiber optic biosensors after sensor head modification and have a high potential for early detection applications of not only AD but possibly also several fatal diseases such as diabetes and cancer.
摘要：
一种新型的光纤生物传感器旨在为监测淀粉样β蛋白片段1-42（Aβ42）以早期检测阿尔茨海默病（AD）的新方法。该传感器是通过在纯氢氟酸溶液中从单模光纤环路中蚀刻一部分光纤制成的，并用作局部光学折射计（LOR）来监测人工脑脊液（ACSF）中Aβ42浓度的变化。光纤环振下光谱(FLRDS)技术是一种低成本的超灵敏测量技术,高灵敏度,实时测量,连续测量和便携性特征，首次与光纤传感器一起用于在ACSF环境中检测生物特征。这里,测量是基于总光学损失检测，当特殊制造的传感器头浸入有和没有不同浓度的Aβ42生物标志物的ACSF溶液，因为进行了整体折射率变化。在空气中测量传感器头的基线稳定性和参考衰铃时间为0.87%和441.6μs3.9μs,分别。之后,当传感器头浸入去离子水中时，测量系统的总光学损耗，ACSF解决方案,和ACSF溶液中含有不同浓度的Aβ42。通过LOR检测到2ppm的最低Aβ42浓度。结果表明，用于FLRDS系统设计的单模光纤制造的LOR是有希望的候选人，可以在传感器头修改后用作光纤生物传感器，并且不仅在AD的早期检测应用中具有很高的潜力，而且可能在糖尿病和癌症等几种致命疾病的早期检测应用中也具有很高的潜力。
