Damiati Samar, Sopstad Sindre, Peacock Martin, Akhtar Ahmad S, Pinto Ines, Soares Ruben R G, Russom Aman
Department of BiochemistryFaculty of ScienceKing Abdulaziz University Jeddah 21589 Saudi Arabia.
Division of NanobiotechnologyDepartment of Protein Science, Science for Life LaboratoryKTH Royal Institute of Technology 171 21 Stockholm Sweden.
IEEE Sens J. 2021 Mar 24;21(12):13060-13067. doi: 10.1109/JSEN.2021.3068922. eCollection 2021 Jun 15.
Since the COVID-19 outbreak was declared a pandemic by the World Health Organization (WHO) in March 2020, ongoing efforts have been made to develop sensitive diagnostic platforms. Detection of viral RNA provides the highest sensitivity and specificity for detection of early and asymptomatic infections. Thus, this work aimed at developing a label-free genosensor composed of graphene as a working electrode that could be embedded into a flex printed circuit board (FPCB) for the rapid, sensitive, amplification-free and label-free detection of SARS-CoV-2. To facilitate liquid handling and ease of use, the developed biosensor was embedded with a user-friendly reservoir chamber. As a proof-of-concept, detection of a synthetic DNA strand matching the sequence of ORF1ab was performed as a two-step strategy involving the immobilization of a biotinylated complementary sequence on a streptavidin-modified surface, followed by hybridization with the target sequence recorded by the differential pulse voltammetric (DPV) technique in the presence of a ferro/ferricyanide redox couple. The effective design of the sensing platform improved its selectivity and sensitivity and allowed DNA quantification ranging from 100 fg/mL to [Formula: see text]/mL. Combining the electrochemical technique with FPCB enabled rapid detection of the target sequence using a small volume of the sample (5-[Formula: see text]). We achieved a limit-of-detection of 100 fg/mL, whereas the predicted value was ~33 fg/mL, equivalent to approximately [Formula: see text] copies/mL and comparable to sensitivities provided by isothermal nucleic acid amplification tests. We believe that the developed approach proves the ability of an FPCB-implemented DNA sensor to act as a potentially simpler and more affordable diagnostic assay for viral infections in Point-Of-Care (POC) applications.
自2020年3月世界卫生组织（WHO）宣布新冠疫情为大流行以来，人们一直在努力开发灵敏的诊断平台。病毒RNA检测对于早期和无症状感染的检测具有最高的灵敏度和特异性。因此，这项工作旨在开发一种以石墨烯为工作电极的无标记基因传感器，该传感器可嵌入柔性印刷电路板（FPCB）中，用于快速、灵敏、无需扩增和无标记地检测严重急性呼吸综合征冠状病毒2（SARS-CoV-2）。为便于液体处理和使用，所开发的生物传感器嵌入了一个用户友好的储液腔室。作为概念验证，对与开放阅读框1ab（ORF1ab）序列匹配的合成DNA链进行检测，采用两步策略，包括将生物素化的互补序列固定在链霉亲和素修饰的表面，然后与在亚铁氰化钾/铁氰化钾氧化还原对存在下通过差分脉冲伏安法（DPV）技术记录的目标序列杂交。传感平台的有效设计提高了其选择性和灵敏度，并允许DNA定量范围为100 fg/mL至[公式：见原文]/mL。将电化学技术与FPCB相结合，能够使用少量样品（5-[公式：见原文]）快速检测目标序列。我们实现了100 fg/mL的检测限，而预测值约为33 fg/mL，相当于约[公式：见原文]拷贝/mL，与等温核酸扩增试验提供的灵敏度相当。我们相信，所开发的方法证明了FPCB实现的DNA传感器有能力在即时检测（POC）应用中作为一种潜在更简单、更经济的病毒感染诊断测定方法。
