Institute of Molecular Biology and Biotechnology-FORTH , 100 N. Plastira Str. , Heraklion 70013 , Greece.
Department of Biology , University of Crete , Voutes , Heraklion 70013 , Greece.
ACS Sens. 2019 May 24;4(5):1329-1336. doi: 10.1021/acssensors.9b00264. Epub 2019 Apr 25.
The objective of this work is to develop a methodology and associated platform for nucleic acid detection at the point-of-care (POC) that is sensitive, user-friendly, affordable, rapid, and robust. The heart of this system is an acoustic wave sensor, based on a Surface Acoustic Wave (SAW) or Quartz Crystal Microbalance (QCM) device, which is employed for the label-free detection of isothermally amplified target DNA. Nucleic acids amplification and detection is demonstrated inside three crude human samples, i.e., whole blood, saliva, and nasal swab, spiked in with 10-100 Salmonella cells. To qualify for POC applications, a portable platform was developed based on 3D printing, integrating inside a single box: (i) simple fluidics based on plastic tubing and a mini peristaltic pump, (ii) a heating plate combined with disposable reaction tubes for isothermal amplification; (iii) a mini antenna analyzer operated through a tablet; and (iv) an acoustic wave device housing unit. The simplicity of the method combined with smartphone operation and detection, rapid sample-to-answer analysis time (30 min), and high performance (detection limit 4 × 10 CFU/ml) in three of the most important human samples in diagnostics suggest that the methodology could become a tool of choice for nucleic acid detection at the POC. In addition, the low cost of the platform and assay holds promise for its adoption in resource limited areas. The acoustic detection method is shown to give similar results with a standard colorimetric assay carried out in saliva and nasal swab but can also be used to detect nucleic acids inside whole blood, where a colorimetric assay failed to perform.
本工作旨在开发一种在即时护理（POC）点进行核酸检测的方法和相关平台，该平台具有灵敏度高、用户友好、价格合理、快速和稳健的特点。该系统的核心是一种基于声波传感器的方法，该传感器基于表面声波（SAW）或石英晶体微天平（QCM）器件，用于对等温扩增的靶 DNA 进行无标记检测。在三个粗人样本中，即全血、唾液和鼻腔拭子中，进行了核酸扩增和检测，这些样本中加入了 10-100 个沙门氏菌细胞。为了符合 POC 应用的要求，基于 3D 打印开发了一种便携式平台，该平台将以下各项集成在一个盒子中：（i）基于塑料管和微型蠕动泵的简单流体学；（ii）用于等温扩增的加热板和一次性反应管；（iii）通过平板电脑操作的迷你天线分析仪；以及（iv）声波器件外壳单元。该方法简单，结合智能手机操作和检测，快速进行样本到答案的分析（30 分钟），并且在诊断中三个最重要的人样本中的性能（检测限为 4×10 CFU/ml）很高，这表明该方法可以成为即时护理点核酸检测的首选方法。此外，该平台和检测的低成本有望在资源有限的地区得到采用。声波检测方法在唾液和鼻腔拭子中的标准比色法检测中给出了相似的结果，但也可用于检测全血中的核酸，而比色法在全血中无法进行检测。
