免标记氧化石墨烯覆膜光纤珐珀生物传感技术研究

Optical fiber label-free biosensor has high research value and good application prospect in the field of bio-sensing. How to improve the sensitivity, stability, repeatability and specificity of the biosensor is a critical problem. The combination of graphene oxide with properties of high refractive index, favorable transparence, large specific surface and optical fiber Fabry-Perot sensor is proposed in this project. And with this novel optical fiber biosensor, the label-free detecting of biological reaction can be realized by detecting the refractive index or the effective thickness of the bio-membrane generated in the biological reaction. Based on the theory of Fresnel reflection and multiple-beam interference, the refractive index and bio-membrane thickness sensing model is established. The optical fiber Fabry-Perot sensor based on hollow-core photonic crystal fiber is designed. The coating process of graphene oxide film on the sensor end is investigated, and the effect of film upon the sensor’s performance is analyzed to optimize the coating process. The immobilization of antibody on sensor is studied and the antigen sensing interface is constructed. A bio-sensing system is designed for the immunity experiments, and the antigen-antibody reaction is characterized by the interference spectrum of the sensor. This project aims to explore a novel graphene oxide coated optical fiber Fabry-Perot biosensor with advanced performance. The implementation of this project has significant meaning in promoting the development of optical fiber label-free biosensor.

免标记光纤生物传感器在生物传感领域具有很高的研究价值和应用潜力，如何提高传感器的灵敏度、稳定性、重复性和特异性是目前存在的关键性难题。本项目提出将具有高折射率、良好透光率及较大比表面积的氧化石墨烯材料与光纤珐珀传感器相结合，构建一种新型生物传感器，通过检测生物反应过程中生物膜折射率或有效厚度的变化来实现生物免疫反应的免标记检测。基于菲涅尔反射原理和多光束干涉原理，建立折射率及膜厚检测模型；利用空芯光子晶体光纤设计光纤珐珀传感器，研究传感器端面氧化石墨烯薄膜的制备方法，分析覆膜对传感器性能的影响，优化覆膜工艺；研究覆膜传感器端面抗体的固定技术，构建抗原检测界面，设计生物传感系统，利用传感器的反射干涉谱来表征抗原抗体反应，实现生物免疫反应检测。本项目拟在利用氧化石墨烯覆膜来进一步提高光纤珐珀生物传感器的检测性能，项目的实施对于推进免标记光纤生物传感器的发展具有重要意义。

光纤传感器与免标记生物检测技术相结合的免标记光纤生物传感器在生物医学、临床诊断、药物分析、环境监测及军事生化检测等领域具有极大的发展潜力和应用前景。但目前免标记光纤生物传感器仍处于实验室研究阶段，如何进一步提高免标记光纤生物传感器的灵敏度、抗干扰能力、稳定性、重复性和特异性等是急需解决的难题。本项目主要对基于空芯光子晶体光纤的光纤珐-珀免标记生物传感器进行了理论分析和初步的实验验证，并提出利用新型碳纳米材料——氧化石墨烯构建生物传感检测界面，来提高生物分子的修饰效果，进而提高生物传感器的检测性能。首先，项目对基于HCPCF的光纤F-P传感器进行了理论研究，表明了通过解调干涉谱条纹对比度和波长，可以实现对外界折射率和温度的同时测量。然后，项目采用电弧放电熔接法制作了基于HCPCF的光纤F-P传感器，并提出了一种光谱差分积分计算的数据分析方法研究，提高了折射率解调结果的准确性。其次，项目对基于HCPCF的光纤F-P免标记免疫传感器的可行性进行了研究，提出了氧化石墨烯覆膜的光纤F-P免标记免疫传感器，免疫实验验证了氧化石墨烯覆膜对于传感器检测性能的提升。最后，以壳聚糖覆膜的光纤F-P湿度传感器为代表，对基于HCPCF的光纤F-P传感器在生物医学等领域湿度检测的应用进行了扩展研究。这些研究成果对于提高生物传感器的检测性能具有十分重要的意义。