Division of Engineering in Medicine, Brigham and Women's Hospital-Harvard Medical School , 75 Francis Street, Boston, Massachusetts 02115, United States.
ACS Sens. 2017 Nov 22;2(11):1713-1720. doi: 10.1021/acssensors.7b00671. Epub 2017 Nov 10.
Nucleic acid detection is of paramount importance in monitoring of microbial pathogens in food safety and infectious disease diagnostic applications. To address these challenges, a rapid, cost-effective label-free technique for nucleic acid detection with minimal instrumentations is highly desired. Here, we present paper microchip to detect and quantify nucleic acid using colorimetric sensing modality. The extracted DNA from food samples of meat as well as microbial pathogens was amplified utilizing loop-mediated isothermal amplification (LAMP). LAMP amplicon was then detected and quantified on a paper microchip fabricated in a cellulose paper and a small wax chamber utilizing crystal violet dye. The affinity of crystal violet dye toward dsDNA and positive signal were identified by changing the color from colorless to purple. Using this method, detection of Sus scrofa (porcine) and Bacillus subtilis (bacteria) DNA was possible at concentrations as low as 1 pg/μL (3.43 × 10 copies/μL) and 10 pg/μL (2.2 × 10 copies/μL), respectively. This strategy can be adapted for detection of other DNA samples, with potential for development of a new breed of simple and inexpensive paper microchip at the point-of-need.
核酸检测在食品安全中微生物病原体监测和传染病诊断应用中至关重要。为了解决这些挑战，人们非常希望有一种快速、经济高效且无需仪器的核酸检测方法。在这里，我们提出了一种使用比色传感模式检测和定量核酸的纸微芯片。从肉类食品样本和微生物病原体中提取的 DNA 利用环介导等温扩增（LAMP）进行扩增。然后，在纤维素纸和小蜡室制成的纸微芯片上利用结晶紫染料检测和定量 LAMP 扩增子。结晶紫染料对 dsDNA 的亲和力和阳性信号通过从无色变为紫色来识别。使用这种方法，可以在低至 1pg/μL（3.43×10 拷贝/μL）和 10pg/μL（2.2×10 拷贝/μL）的浓度下检测到 Sus scrofa（猪）和 Bacillus subtilis（细菌）的 DNA。该策略可以适应其他 DNA 样本的检测，有可能开发出一种新型简单且经济实惠的即时检测用纸质微芯片。
