Electrical Engineering Department, Institute of Information and Communication Technologies Electronics and Applied Mathematics, UCLouvain, 1348 Louvain-la-Neuve, Belgium.
Laboratory of Food and Environmental Microbiology, Earth and Life Institute, UCLouvain, 1348 Louvain-la-Neuve, Belgium.
Biosensors (Basel). 2021 Jan 20;11(2):27. doi: 10.3390/bios11020027.
Porous silicon (PSi) has been widely used as a biosensor in recent years due to its large surface area and its optical properties. Most PSi biosensors consist in close-ended porous layers, and, because of the diffusion-limited infiltration of the analyte, they lack sensitivity and speed of response. In order to overcome these shortcomings, PSi membranes (PSiMs) have been fabricated using electrochemical etching and standard microfabrication techniques. In this work, PSiMs have been used for the optical detection of lysate. Before detection, the bacteria are selectively lysed by PlyB221, an endolysin encoded by the bacteriophage Deep-Blue targeting . The detection relies on the infiltration of bacterial lysate inside the membrane, which induces a shift of the effective optical thickness. The biosensor was able to detect a bacterial lysate, with an initial bacteria concentration of 10 colony forming units per mL (CFU/mL), in only 1 h. This proof-of-concept also illustrates the specificity of the lysis before detection. Not only does this detection platform enable the fast detection of bacteria, but the same technique can be extended to other bacteria using selective lysis, as demonstrated by the detection of , selectively lysed by lysostaphin.
多孔硅（PSi）由于其较大的表面积和光学性质，近年来已被广泛用作生物传感器。大多数 PSi 生物传感器由封闭的多孔层组成，由于分析物的扩散限制渗透，它们缺乏灵敏度和响应速度。为了克服这些缺点，使用电化学蚀刻和标准微制造技术制造了 PSi 膜（PSiMs）。在这项工作中，PSiMs 用于裂解物的光学检测。在检测之前，通过 PlyB221 选择性裂解细菌，PlyB221 是一种由噬菌体 Deep-Blue 编码的内切酶，靶向 。检测依赖于细菌裂解物渗透到膜内，这会引起有效光学厚度的变化。该生物传感器能够在 1 小时内检测到初始细菌浓度为每毫升 10 个菌落形成单位（CFU/mL）的细菌裂解物。该概念验证还说明了检测前裂解的特异性。该检测平台不仅能够快速检测细菌，而且还可以通过选择性裂解将相同的技术扩展到其他细菌，如通过溶葡萄球菌素选择性裂解的 检测所证明的那样。
