Dept. of Chemical Engineering, Indian Institute of Technology Delhi, Delhi 110016, India.
Langmuir. 2024 Oct 22;40(42):21907-21930. doi: 10.1021/acs.langmuir.4c01907. Epub 2024 Oct 10.
Conventional approaches for bacterial cell analysis are hindered by lengthy processing times and tedious protocols that rely on gene amplification and cell culture. Impedance spectroscopy has emerged as a promising tool for efficient real-time bacterial monitoring, owing to its simple, label-free nature and cost-effectiveness. However, its limited practical applications in real-world scenarios pose a significant challenge. In this review, we provide a comprehensive study of impedance spectroscopy and its practical utilization in bacterial system measurements. We begin by outlining the fundamentals of impedance theory and modeling, specific to bacterial systems. We then offer insights into various strategies for bacterial cell detection and discuss the role of impedance spectroscopy in antimicrobial susceptibility testing (AST) and single-cell analysis. Additionally, we explore key aspects of impedance system design, including the influence of electrodes, media, and cell enrichment techniques on the sensitivity, specificity, detection speed, concentration accuracy, and cost-effectiveness of current impedance biosensors. By combining different biosensor design parameters, impedance theory, and detection principles, we propose that impedance applications can be expanded to point-of-care diagnostics, enhancing their practical utility. This Perspective focuses exclusively on ideally polarizable (fully capacitive) electrodes, excluding any consideration of charge transfer resulting from Faradaic reactions.
传统的细菌细胞分析方法受到冗长的处理时间和繁琐的协议的阻碍，这些协议依赖于基因扩增和细胞培养。由于其简单、无标记和具有成本效益的特点，阻抗谱分析已成为一种很有前途的实时细菌监测工具。然而，其在实际场景中的应用有限，这是一个重大挑战。在这篇综述中，我们全面研究了阻抗谱分析及其在细菌系统测量中的实际应用。我们首先概述了适用于细菌系统的阻抗理论和模型的基本原理。然后，我们深入探讨了各种细菌细胞检测策略，并讨论了阻抗谱分析在抗菌药物敏感性测试（AST）和单细胞分析中的作用。此外，我们还研究了阻抗系统设计的关键方面，包括电极、介质和细胞富集技术对当前阻抗生物传感器的灵敏度、特异性、检测速度、浓度准确性和成本效益的影响。通过结合不同的生物传感器设计参数、阻抗理论和检测原理，我们提出阻抗应用可以扩展到即时诊断领域，从而提高其实用性。本观点仅关注理想可极化（全电容）电极，不考虑任何由于法拉第反应引起的电荷转移。
