Institute of Optical Imaging and Sensing, Shenzhen Key Laboratory for Minimal Invasive Medical Technologies, Graduate School at Shenzhen, Tsinghua University, Shenzen 518055, China; Department of Physics, Tsinghua University, Beijing 100084, China.
Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.
Biosens Bioelectron. 2015 May 15;67:230-6. doi: 10.1016/j.bios.2014.08.021. Epub 2014 Aug 18.
Label-free biosensing based on optical waveguide spectroscopy of silica nanotube (SNT) arrays is realized with high sensitivity. The SNT arrays fabricated using a porous anodic alumina (PAA) template assisted by surface sol-gel (SSG) method showed a high value of 552 reciprocal refractive index unit as the sensing figure of merit by exchanging the sensing environment with water and ethanol. A standard biotin-streptavidin affinity model was tested using the SNT arrays which support a TM1 mode and the fundamental response of the system was investigated. Results show that the response of the SNT arrays for adsorption of streptavidin is higher than the one using substrate without removing the PAA template due to the larger surface area and the stronger electromagnetic field. The limit of detection (LOD) of the SNT arrays for detection of streptavidin was estimated as 93 pM, with the detection time of 40 min. Additionally, the Fresnel calculations suggested higher potential sensitivity of the current system compared to that of the conventional SPR sensors. Thus, the SNT arrays may be used as a versatile platform for high-sensitive label-free optical biosensing due to the high performance and the large potential of the surface functionality.
基于二氧化硅纳米管（SNT）阵列的光波导光谱的无标记生物传感具有高灵敏度。使用多孔阳极氧化铝（PAA）模板辅助的表面溶胶-凝胶（SSG）方法制造的 SNT 阵列在将传感环境与水和乙醇交换时显示出 552 分之一的高折射率单位值作为传感品质因数。使用支持 TM1 模式的 SNT 阵列测试了标准的生物素-链霉亲和素亲和模型，并研究了系统的基本响应。结果表明，由于较大的表面积和较强的电磁场，SNT 阵列对链霉亲和素的吸附响应高于不去除 PAA 模板的基底的响应。SNT 阵列检测链霉亲和素的检测限（LOD）估计为 93 pM，检测时间为 40 分钟。此外，菲涅尔计算表明，与传统的 SPR 传感器相比，当前系统具有更高的潜在灵敏度。因此，由于高性能和表面功能的巨大潜力，SNT 阵列可用作高灵敏度无标记光学生物传感的通用平台。
