Biomedical sensor that sense different molecules with a high refractive index sensitivity is proposed in this work. Plasmonic nanospiral antenna is mounted on a top surface of an optical fiber to reflect the incident optical signal back to the fiber. The reflected signal depends on the nanospiral antenna material, dimensions and the surrounding medium. Using streptavidin molecule, the nanospiral antenna have been simulated based on finite difference time domain method to optimize its dimensions. The optimum dimensions are 10 nm, 55 nm and 40 nm for inner-outer thicknesses and height respectively. The introduced biosensor can detect different molecules based on surface plasmonic resonance, which depends on the shifting of the peak wavelength according to the molecules type. The detected molecules are Streptavidin, Urease, Uricase molecules and Glucose oxidase and Cholesterol oxidase enzymes with a high sensitivity. The maximum refractive index sensitivity is obtained when sensing cholesterol oxidase molecules with 3028 nm/RIU at 3.58 μm peak wavelength. Figure of merit and quality factor are also calculated for all detected molecules. Finally, electric field and optical power, before and after binding, of the reflected signal are illustrated and discussed.

中文翻译：

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基于光纤的等离子螺旋纳米天线的高性能分子检测生物传感器。

在这项工作中提出了一种生物医学传感器，该传感器可感知具有高折射率敏感性的不同分子。等离子体纳米螺旋天线安装在光纤的顶面上，以将入射的光信号反射回光纤。反射信号取决于纳米螺旋天线的材料，尺寸和周围的介质。使用链霉亲和素分子，基于时域有限差分法模拟了纳米螺旋天线，以优化其尺寸。内外厚度和高度的最佳尺寸分别为10 nm，55 nm和40 nm。引入的生物传感器可以基于表面等离子体共振检测不同的分子，表面等离子体共振取决于峰波长根据分子类型的变化。检测到的分子是链霉亲和素，脲酶，尿酸酶分子和葡萄糖氧化酶和胆固醇氧化酶具有很高的敏感性。当在3.58处检测3028 nm / RIU的胆固醇氧化酶分子时，可获得最大折射率灵敏度μ米峰值波长。还为所有检测到的分子计算了品质因数和品质因数。最后，说明并讨论了反射信号束缚前后的电场和光功率。