AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow, Poland.
Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Weigla 12, 53-114 Wroclaw, Poland.
Biosens Bioelectron. 2016 Jan 15;75:328-36. doi: 10.1016/j.bios.2015.08.019. Epub 2015 Aug 12.
In this paper, the authors present a new type of highly sensitive label-free microwave sensor in a form of interdigital capacitor coated with T4 bacteriophage gp37 adhesin. The adhesin binds Escherichia coli B (E. coli B) by precise recognizing its bacterial host lipopolysaccharide (LPS). The C-terminal part of the adhesin consists of the receptor-binding amino acid residues which are involved in a specific interaction with two terminal glucose residues of the bacterial LPS. The change of the sensors' capacitance and conductance as a subject to LPS presence is an indicator of the detection. The measurements in the frequency range of 0-3GHz utilizing vector network analyzer have been carried out at different concentrations to verify experimentally the proposed method. The measured capacitance change between the reference and the biofunctionalized sensor equals 15% in the entire frequency range and the measured conductance change exceeds 19%. The changes of both parameters can be used as good indicators of the LPS detection. The selectivity has been confirmed by the ELISA experiments and tested by sensor measurements with lipopolysaccharide (LPS) from E. coli B, E. coli 056, E. coli 0111, Pseudomonas aeruginosa NBRC 13743 and Hafnia alvei 1185.
本文提出了一种新型的高灵敏度、无标记的微波传感器，其形式为涂有 T4 噬菌体 gp37 粘附素的叉指电容器。该粘附素通过精确识别其细菌宿主脂多糖（LPS）来结合大肠杆菌 B（E. coli B）。粘附素的 C 末端包含参与与细菌 LPS 的两个末端葡萄糖残基特异性相互作用的受体结合氨基酸残基。传感器电容和电导随 LPS 存在而变化是检测的一个指标。利用矢量网络分析仪在 0-3GHz 的频率范围内进行了不同浓度的测量，以实验验证所提出的方法。在整个频率范围内，参考和生物功能化传感器之间测量的电容变化等于 15%，测量的电导变化超过 19%。这两个参数的变化都可以作为 LPS 检测的良好指标。通过 ELISA 实验证实了选择性，并通过传感器测量用大肠杆菌 B、大肠杆菌 056、大肠杆菌 0111、铜绿假单胞菌 NBRC 13743 和哈夫尼亚菌 1185 的脂多糖（LPS）进行了测试。
