Grup de Sensors i Biosensors, Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
IIT Madras Bioincubator, Indian Institute of Technology, Chennai 600113, India.
Sensors (Basel). 2021 Mar 3;21(5):1749. doi: 10.3390/s21051749.
Isothermal amplification techniques are emerging nowadays for the rapid and accurate detection of pathogenic bacteria in low resource settings, where many infectious diseases are endemic, and the lack of reliable power supply, trained personnel and specialized facilities pose critical barriers for timely diagnosis. This work addresses the detection of based on DNA isothermal amplification performed on magnetic particles (MPs) followed by electrochemical genosensing on disposable electrodes by square-wave voltammetry. In this approach, the bacterial DNA is preconcentrated using a target-specific magnetic probe and then amplified on the MPs by rolling circle amplification (RCA). Two different electrochemical readout methods for the RCA amplicons are tested. The first one relied on the labelling of the magnetic RCA product with a digoxigenin probe followed by the incubation with antiDIG-HRP antibody as electrochemical reporter. In the second case, the direct detection with an HRP-probe was performed. This latter strategy showed an improved analytical performance, while simultaneously avoiding the use of thermocyclers or bulky bench top equipment.
等温扩增技术在如今迅速发展，可用于在资源匮乏的环境中快速、准确地检测致病菌。在这些环境中，存在许多地方性传染病，缺乏可靠的电力供应、训练有素的人员和专业设施，这对及时诊断造成了重大障碍。本工作针对的是基于 DNA 等温扩增在磁性颗粒 (MPs) 上进行的检测，随后通过方波伏安法在一次性电极上进行电化学生物传感。在这种方法中，使用靶标特异性磁性探针对细菌 DNA 进行预浓缩，然后通过滚环扩增 (RCA) 在 MPs 上进行扩增。对 RCA 扩增子的两种不同电化学生物读出方法进行了测试。第一种方法依赖于用地高辛探针标记磁性 RCA 产物，然后用抗 DIG-HRP 抗体孵育作为电化学生物报告物。在第二种情况下，直接用 HRP 探针进行检测。后一种策略显示出了改进的分析性能，同时避免了使用热循环仪或体积庞大的台式设备。
