近年来,全细胞生物传感器(WCB)已成为环境监测和现场分析物检测的有效方法。这些生物传感器利用微生物的生物装置来识别特定的分析物,提供灵敏度方面的优势,特异性,和实时监控功能。生物传感器开发的一个关键障碍在于确保细胞与表面的牢固附着。实用的关键步骤。在这项研究中,我们提出了一种全面的方法来解决这一挑战,通过工程大肠杆菌细胞通过Curli生物膜途径固定在纸上。此外,将纤维素结合肽结构域掺入CsgA生物膜蛋白可增强细胞对纸张表面的粘附,从而提高生物传感器的功效。为了展示这个平台的多功能性,我们开发了铜的WCB,优化以表现出可辨别的响应,即使是用肉眼。为了确认其适合实际现场使用,我们在各种环境条件下表征了我们的铜传感器-温度,盐度,和pH值模拟现实世界的场景。配备生物传感器的纸盘可以冷冻干燥,以便在现场应用中部署,提供一种长期储存而不损失灵敏度的实用方法纸盘显示出持续的功能性和可行性,即使在储存数月后,铜的检测极限为5μM,肉眼可见的信号水平。生物膜介导的表面附着和分析物传感可以独立工程,允许根据需要灵活利用这个平台。随着铜传感作为概念验证研究的实施,我们强调了WCB作为现场检测多种分析物的有希望的途径的潜力。
In recent years, whole-cell biosensors (WCBs) have emerged as a potent approach for environmental monitoring and on-site analyte detection. These biosensors harness the biological apparatus of microorganisms to identify specific analytes, offering advantages in sensitivity, specificity, and real-time monitoring capabilities. A critical hurdle in biosensor development lies in ensuring the robust attachment of cells to surfaces, a crucial step for practical utility. In this study, we present a comprehensive approach to tackle this challenge via engineering Escherichia coli cells for immobilization on paper through the Curli biofilm pathway. Furthermore, incorporating a cellulose-binding peptide domain to the CsgA biofilm protein enhances cell adhesion to paper surfaces, consequently boosting biosensor efficacy. To demonstrate the versatility of this platform, we developed a WCB for copper, optimized to exhibit a discernible response, even with the naked eye. To confirm its suitability for practical field use, we characterized our copper sensor under various environmental conditions-temperature, salinity, and pH-to mimic real-world scenarios. The biosensor-equipped paper discs can be freeze-dried for deployment in on-site applications, providing a practical method for long-term storage without loss of sensitivity paper discs demonstrate sustained functionality and viability even after months of storage with 5 μM limit of detection for copper with visible-to-naked-eye signal levels. Biofilm-mediated surface attachment and analyte sensing can be independently engineered, allowing for flexible utilization of this platform as required. With the implementation of copper sensing as a proof-of-concept study, we underscore the potential of WCBs as a promising avenue for the on-site detection of a multitude of analytes.