Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, 51666 16471, Tabriz, Iran.
Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, 51666 16471, Tabriz, Iran.
Chemosphere. 2022 Feb;288(Pt 2):132531. doi: 10.1016/j.chemosphere.2021.132531. Epub 2021 Oct 12.
Shigella dysenteriae, a gram-negative bacterium, which results in the most infectious of bacterial shigellosis and dysenteries. In this study, an innovative gene detection platform based on label-free DNA sequences was developed to detect Shigella dysenteriae in human plasma samples. The porous and honeycomb-like structure of biochar (BC) was first synthesized through a pyrolysis process. Then, the produced biochar was effectively decorated with flower-like MoS nanosheets (MoS/BC). The resulting nanocomposite was incorporated with Au nanoparticles (AuNPs) by applying chronoamperometry technique, and then the subsequent product including MoS nanosheets, biochar and AuNPs were immobilized on the Au electrode surface and used for modifier agent in electrochemical bio-assays. Structural and morphological study of the synthesized compounds were investigated using various characterization methods such as FE-SEM, TEM, EDS, FTIR, and XRD. Various electrochemical techniques including cyclic voltammetry (CV) and Differential pulse anodic stripping voltammetry (DPASV) have been used to investigate the applicability of the fabricated genosensing bio-assay. Under optimal conditions, LOD and LOQ were calculated 9.14 fM and 0.018 pM respectively. In addition, a linear range from 0.01 to 100 pM was obtained for single stranded-target DNA (ss-tDNA), with R of 0.9992. The recoveries ranged from 98.0 to 101.3%. The fabricated bio-detection assay demonstrated high selectivity for 1, 2, and 3 base mismatch sequences. In addition, a negative control of the gene detection platform which was performed to study selectivity was provided by ss-tDNA from Haemophilusinfluenzae, and Salmonella typhimurium. Moreover, it is important to mention that the organized bioassay is simply reusable and reproducible with the RSD% (relative standard deviation) ˂ 5 to next detection assays.
志贺氏菌，一种革兰氏阴性菌，可导致最具传染性的细菌性痢疾和痢疾。在这项研究中，开发了一种基于无标记 DNA 序列的创新基因检测平台，用于检测人血浆样本中的志贺氏菌。首先通过热解过程合成多孔蜂窝状结构的生物炭（BC）。然后，用花状 MoS 纳米片（MoS/BC）有效地修饰所产生的生物炭。通过计时安培技术将所得纳米复合材料与金纳米颗粒（AuNPs）结合，然后将包括 MoS 纳米片、生物炭和 AuNPs 的后续产物固定在 Au 电极表面，并用作电化学生物测定中的修饰剂。通过各种表征方法，如 FE-SEM、TEM、EDS、FTIR 和 XRD，研究了合成化合物的结构和形态。各种电化学技术，包括循环伏安法（CV）和差分脉冲阳极溶出伏安法（DPASV），已用于研究所制备的基因传感生物测定的适用性。在最佳条件下，LOD 和 LOQ 分别计算为 9.14 fM 和 0.018 pM。此外，单链靶 DNA（ss-tDNA）的线性范围为 0.01 至 100 pM，R 为 0.9992。回收率范围为 98.0 至 101.3%。所制备的生物检测分析对 1、2 和 3 个碱基错配序列具有高选择性。此外，还提供了基因检测平台的阴性对照，即来自流感嗜血杆菌和鼠伤寒沙门氏菌的 ss-tDNA，以研究选择性。此外，重要的是要提到，组织生物测定具有简单的可重复使用性和可重复性，下一次检测分析的 RSD%（相对标准偏差）<5。
