Department of Microbiology and Virology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Antimicrobial Resistance Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran.
Department of Microbiology and Virology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Antimicrobial Resistance Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
Talanta. 2022 Feb 1;238(Pt 2):123049. doi: 10.1016/j.talanta.2021.123049. Epub 2021 Nov 9.
Mycobacterium simiae has been reported to be the most prevalent species of Nontuberculous mycobacteria (NTM) in many countries. As both phenotypic and molecular detection of M. simiae and other NTMs have limitations, finding an accurate, fast, and low-cost diagnostic method is critical for the management of infections. Here, we report the development of a new type of label-free electrochemical biosensor using a gold electrode decorated with l-cysteine/PAMAM dendrimer for specific targeting of M. simiae ITS sequence. DNA hybridization was monitored by measuring changes in the free guanine electrical signal with changing ssDNA target concentrations by differential pulse voltammetry (DPV) method. Response surface methodology (RSM) was applied for the optimization of variables affecting biosensor response. Under optimal conditions, the biosensor revealed a wide linear range from 10 M to 10 M and a detection limit of 1.40 fM. The fabricated biosensor showed an excellent selectivity to M. simiae in the presence of other similar pathogenic bacteria. Moreover, experimental results confirmed that this biosensor exhibited great precision and high reproducibility, hence provides a low-cost, label-free, and faster detection analysis, representing a novel strategy in detecting other NTMs.
猿分枝杆菌已被报道为许多国家中最常见的非结核分枝杆菌（NTM）物种。由于表型和分子检测法对猿分枝杆菌和其他 NTM 都具有局限性，因此找到一种准确、快速且低成本的诊断方法对于感染的管理至关重要。在这里，我们报告了一种新型的无标记电化学生物传感器的开发，该传感器使用金电极修饰 l-半胱氨酸/PAMAM 树状大分子来特异性靶向猿分枝杆菌 ITS 序列。通过差分脉冲伏安法（DPV）方法，通过测量随着 ssDNA 靶标浓度变化而变化的游离鸟嘌呤电信号来监测 DNA 杂交。响应面法（RSM）用于优化影响生物传感器响应的变量。在最佳条件下，该生物传感器显示出从 10 pM 到 10 pM 的宽线性范围和 1.40 fM 的检测限。在存在其他类似致病性细菌的情况下，所制备的生物传感器对猿分枝杆菌表现出优异的选择性。此外，实验结果证实，该生物传感器表现出良好的精度和高重现性，因此提供了一种低成本、无标记和更快的检测分析方法，代表了检测其他 NTM 的一种新策略。
