Bioluminescent bacteria whole-cell biosensors (WCBs) have been widely used in a range of sensing applications in environmental monitoring and medical diagnostics. However, most of them use planktonic bacteria cells that require complicated signal measurement processes and therefore limit the portability of the biosensor device. In this study, a simple and low-cost immobilization method was examined. The bioluminescent bioreporter bacteria was absorbed on a filter membrane disk. Further optimization of the immobilization process was conducted by comparing different surface materials (polyester and parafilm) or by adding glucose and ampicillin. The filter membrane disks with immobilized bacteria cells were stored at −20 °C for three weeks without a compromise in the stability of its biosensing functionality for water toxicants monitoring. Also, the bacterial immobilized disks were integrated with smartphones-based signal detection. Then, they were exposed to water samples with ethanol, chloroform, and H₂O₂, as common toxicants. The sensitivity of the smartphone-based WCB for the detection of ethanol, chloroform, and H₂O₂ was 1% (v/v), 0.02% (v/v), and 0.0006% (v/v), respectively. To conclude, this bacterial immobilization approach demonstrated higher sensitivity, portability, and improved storability than the planktonic counterpart. The developed smartphone-based WCB establishes a model for future applications in the detection of environmental water toxicants.

中文翻译：

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基于martphone的全细胞生物传感器平台，该方法在滤膜盘上采用固定化方法来监测水毒

生物发光细菌全细胞生物传感器（WCB）已广泛用于环境监测和医学诊断中的各种传感应用中。然而，它们中的大多数使用浮游细菌细胞，其需要复杂的信号测量过程，因此限制了生物传感器装置的便携性。在这项研究中，研究了一种简单且低成本的固定方法。生物发光生物报告细菌被吸收在滤膜盘上。通过比较不同的表面材料（聚酯和封口膜）或添加葡萄糖和氨苄青霉素，可以进一步优化固定化过程。将具有固定细菌细胞的滤膜圆盘在-20°C下保存三周，而不会损害其用于水毒物监测的生物传感功能的稳定性。也，固定细菌的磁盘与基于智能手机的信号检测集成在一起。然后，将它们暴露于含乙醇，氯仿和H的水样品中₂ O ₂，作为常见的毒物。基于智能手机的WCB对乙醇，氯仿和H ₂ O ₂的检测灵敏度_分别为1％（v / v），0.02％（v / v）和0.0006％（v / v）。总而言之，这种细菌固定方法比浮游生物具有更高的敏感性，便携性和更好的保存性。基于智能手机的已开发WCB为将来的环境水毒物检测应用建立了模型。