Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662, Warsaw, Poland.
Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.
Sci Rep. 2024 Oct 4;14(1):23127. doi: 10.1038/s41598-024-70058-6.
This work discusses label-free biosensing application of a double-layer optical fiber interferometer where the second layer tailors the reflection conditions at the external plain and supports changes in reflected optical spectrum when a bio-layer binds to it. The double-layer nanostructure consists of precisely tailored thin films, i.e., titanium (TiO) and hafnium oxides (HfO) deposited on single-mode fiber end-face by magnetron sputtering. It has been shown numerically and experimentally that the approach besides well spectrally defined interference pattern distinguishes refractive index (RI) changes taking place in a volume and on the sensor surface. These are of interest when label-free biosensing applications are considered. The case of myeloperoxidase (MPO) detection-a protein, which concentration rises during inflammation-is reported as an example of application. The response of the sensor to MPO in a concentration range of 1 × 10-5 × 10 g/mL was tested. An increase in the MPO concentration was followed by a redshift of the interference pattern and a decrease in reflected power. The negative control performed using ferritin proved specificity of the sensor. The results reported in this work indicate capability of the approach for diagnostic label-free biosensing, possibly also at in vivo conditions.
这项工作讨论了一种双层光纤干涉仪的无标记生物传感应用，其中第二层调整外部平面的反射条件，并在生物层与之结合时支持反射光光谱的变化。双层纳米结构由精确调整的薄膜组成，即通过磁控溅射沉积在单模光纤端面上的钛 (TiO) 和铪氧化物 (HfO)。已经从数值和实验上证明，该方法除了具有良好光谱定义的干涉图案外，还可以区分在体积中和传感器表面上发生的折射率 (RI) 变化。当考虑无标记生物传感应用时，这些变化是很有意义的。以髓过氧化物酶 (MPO) 检测为例，报道了一种应用。该传感器对浓度范围为 1×10-5×10 g/mL 的 MPO 的响应进行了测试。MPO 浓度的增加伴随着干涉图案的红移和反射功率的降低。使用铁蛋白进行的阴性对照证明了传感器的特异性。本工作中报告的结果表明，该方法有可能用于诊断无标记生物传感，也可能在体内条件下使用。
