The detection and identification of bacteria currently rely on enrichment steps such as bacterial culture and nucleic acid amplification to increase the concentration of target analytes. These steps increase assay time, cost and complexity, making it difficult to realize a truly rapid point-of-care test. Here we report the development of an electrical assay that uses electroactive RNA-cleaving DNAzymes (e-RCDs) to identify specific bacterial targets and subsequently release a DNA barcode for transducing a signal onto an electrical chip. Integrating e-RCDs into a two-channel electrical chip with nanostructured electrodes provides the analytical sensitivity and specificity needed for clinical analysis. The e-RCD assay is capable of detecting 10 CFU (equivalent to 1,000 CFU ml^–1) of Escherichia coli selectively from a panel containing multiple non-specific bacterial species. Clinical evaluation of this assay using 41 patient urine samples demonstrated a diagnostic sensitivity of 100% and specificity of 78% at an analysis time of less than one hour compared with the several hours needed for currently used culture-based methods.

细菌的检测和鉴定目前依靠细菌培养和核酸扩增等富集步骤来提高目标分析物的浓度。这些步骤增加了检测时间、成本和复杂性，使得实现真正快速的即时检测变得困难。在这里，我们报告了一种使用电活性 RNA 切割 DNA 酶 (e-RCD) 来识别特定细菌靶标并随后释放 DNA 条形码以将信号转导到电芯片上的电检测方法的开发。将 e-RCD 集成到具有纳米结构电极的双通道电子芯片中，可提供临床分析所需的分析灵敏度和特异性。e-RCD 检测能够检测 10 CFU（相当于 1,000 CFU ml ^–1）的大肠杆菌选择性地从包含多种非特异性细菌物种的面板中选择。使用 41 名患者尿液样本对该测定进行临床评估，与目前使用的基于培养的方法所需的几个小时相比，在不到一小时的分析时间内，诊断灵敏度为 100%，特异性为 78%。