Zambry Nor Syafirah, Awang Mohd Syafiq, Hamzah Hairul Hisham, Mohamad Ahmad Najib, Khalid Muhammad Fazli, Khim Beh Khi, Bustami Yazmin, Jamaluddin Nurul Fauzani, Ibrahim Fatimah, Aziah Ismail, Abd Manaf Asrulnizam
Centre for Innovation in Medical Engineering (CIME), Faculty of Engineering, Universiti Malaya, 50603 Kuala Lumpur, Malaysia.
Department of Biomedical Engineering, Faculty of Engineering, Universiti Malaya, 50603 Kuala Lumpur, Malaysia.
Anal Methods. 2024 Aug 1;16(30):5254-5262. doi: 10.1039/d4ay00888j.
A highly accurate, rapid, portable, and robust platform for detecting serovar Typhi ( Typhi) is crucial for early-stage diagnosis of typhoid to avert and control the outbreaks of this pathogen, which threaten global public health. This study presents a proof-of-concept for our developed label-free electrochemical DNA biosensor system for Typhi detection, which employs a printed circuit board gold electrode (PCBGE), integrated with a portable potentiostat reader. Initially, the functionalized DNA biosensor and target detection were characterized using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) methods using a benchtop potentiostat. Interestingly, the newly developed DNA biosensor can identify target single-stranded DNA concentrations ranging from 10 nM to 20 μM, achieving a detection limit of 7.6 nM within a brief 5 minute timeframe. Under optimal detection conditions, the DNA biosensor exhibits remarkable selectivity, capable of distinguishing a single mismatch base pair from the target single-stranded DNA sequence. We then evaluated the feasibility of the developed DNA biosensor system as a diagnostic tool by detecting Typhi in 50 clinical samples using a portable potentiostat reader based on the DPV technique. Remarkably, the developed biosensor can distinctly distinguish between positive and negative samples, indicating that the miniaturised DNA biosensor system is practical for detecting Typhi in real biological samples. The developed DNA biosensor device in this work proves to be a promising point-of-care (POC) device for detection due to its swift detection time, uncomplicated design, and streamlined workflow detection system.
一个用于检测伤寒杆菌（Typhi）的高度准确、快速、便携且稳健的平台对于伤寒的早期诊断以避免和控制这种威胁全球公共卫生的病原体的爆发至关重要。本研究展示了我们开发的用于检测Typhi的无标记电化学DNA生物传感器系统的概念验证，该系统采用了印刷电路板金电极（PCBGE），并集成了便携式恒电位仪读数器。最初，使用台式恒电位仪通过循环伏安法（CV）、差分脉冲伏安法（DPV）和电化学阻抗谱（EIS）方法对功能化的DNA生物传感器和目标检测进行了表征。有趣的是，新开发的DNA生物传感器能够识别浓度范围从10 nM到20 μM的目标单链DNA，在短短5分钟内实现了7.6 nM的检测限。在最佳检测条件下，DNA生物传感器表现出显著的选择性，能够从目标单链DNA序列中区分出单个错配碱基对。然后，我们通过使用基于DPV技术的便携式恒电位仪读数器检测50份临床样本中的Typhi，评估了所开发的DNA生物传感器系统作为诊断工具的可行性。值得注意的是，所开发的生物传感器能够明显区分阳性和阴性样本，表明小型化的DNA生物传感器系统在实际生物样本中检测Typhi是可行的。由于其快速的检测时间、简单的设计和简化的工作流程检测系统，本工作中开发的DNA生物传感器装置被证明是一种有前途的用于检测Typhi的即时检测（POC）装置。
