Gold-coated tilted fiber Bragg gratings (TFBGs) have been highly studied over the last years, mainly for biosensing purposes. They present a comb-like spectrum of narrow-band cladding mode resonances that is often demodulated by tracking the change of a selected peak. In this paper, we report a twentyfold more sensitive demodulation method based on the intersection of the upper and lower envelopes of gold-coated TFBG spectra. This method has been successfully applied in biosensing experiments towards the detection of HER2 (Human Epidermal Growth Factor Receptor-2) proteins, a relevant biomarker for breast cancer. Practical improvements have also been implemented. First, a uniform FBG has been superimposed on the TFBG to reduce the read-out wavelength span to 10 nm instead of 70 nm while keeping the temperature-compensated measurements. Second, a micro-fluidic system has been implemented to smoothly deliver the samples to the sensor. These 3 originalities make this sensing platform even more attractive for use in practical applications.

中文翻译：

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通过光谱包络交点解调的等离激元光纤光栅生物传感器


镀金倾斜光纤布拉格光栅（TFBG）在过去几年中得到了深入研究，主要用于生物传感目的。它们呈现出窄带包层模式谐振的梳状频谱，通常通过跟踪选定峰值的变化来解调。在本文中，我们报告了一种基于镀金 TFBG 光谱上下包络相交的灵敏度提高 20 倍的解调方法。该方法已成功应用于检测 HER2（人类表皮生长因子受体-2）蛋白（乳腺癌的相关生物标志物）的生物传感实验。还实施了实际改进。首先，在 TFBG 上叠加均匀的 FBG，将读出波长跨度从 70 nm 减少到 10 nm，同时保持温度补偿测量。其次，采用微流体系统将样品平稳地输送到传感器。这三项独创性使该传感平台在实际应用中更具吸引力。