Department of Chemistry, Sharif University of Technology, Tehran 11155-9516, Iran.
Analyst. 2018 Jul 7;143(13):3191-3201. doi: 10.1039/c8an00725j. Epub 2018 Jun 14.
Herein, we report the development of an electrochemical biosensor for Escherichia coli O157:H7 diagnostic based on amino-functionalized metal-organic frameworks (MOFs) as a new generation of organic-inorganic hybrid nanocomposites. The electrical and morphological properties of MOFs were enhanced by interweaving each isolated MOF crystal with polyaniline (PANI). Subsequent attachment of the amine-modified aptamer to the polyanilinated MOFs was accomplished using glutaraldehyde (GA) as a cross-linking agent. The prepared biocompatible platform was carefully characterized by means of field-emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), and X-ray powder diffraction (XRD) techniques. The biosensor fabrication and its electrochemical characterizations were monitored by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. Differential pulse voltammetry (DPV) was applied to monitoring and quantitation of the interaction between the aptamer and E. coli O157:H7 using methylene blue (MB) as an electrochemical indicator. Changes in the reduction peak current of MB in the presence of E. coli O157:H7 was recorded as an analytical signal and indicated a relationship with the logarithm of the E. coli O157:H7 concentration in the range of 2.1 × 10 to 2.1 × 10 CFU mL with a LOQ of 21 CFU mL and LOD of 2 CFU mL. The electrochemical aptasensor displayed good recovery values for the detection of E. coli O157:H7 in environmental real samples and also could act as a smart device to investigate the effects of antibacterial agents against E. coli O157:H7.
在此，我们报告了一种基于氨基功能化金属有机骨架（MOFs）的电化学大肠杆菌 O157:H7 诊断生物传感器的开发，作为新一代有机-无机杂化纳米复合材料。通过将每个孤立的 MOF 晶体与聚苯胺（PANI）交织，MOFs 的电学和形态性质得到了增强。随后，使用戊二醛（GA）作为交联剂，将胺修饰的适体附着到聚氮化 MOFs 上。通过场发射扫描电子显微镜（FESEM）、能量色散光谱（EDS）、傅里叶变换红外光谱（FT-IR）和 X 射线粉末衍射（XRD）技术对制备的生物相容性平台进行了仔细表征。通过循环伏安法（CV）和电化学阻抗谱（EIS）技术监测生物传感器的制备及其电化学特性。使用亚甲基蓝（MB）作为电化学指示剂，通过差分脉冲伏安法（DPV）监测和定量适体与大肠杆菌 O157:H7 之间的相互作用。记录存在大肠杆菌 O157:H7 时 MB 还原峰电流的变化作为分析信号，并表明与大肠杆菌 O157:H7 浓度的对数呈线性关系，范围为 2.1×10 至 2.1×10 CFU mL，LOQ 为 21 CFU mL，LOD 为 2 CFU mL。电化学适体传感器对环境实际样品中大肠杆菌 O157:H7 的检测具有良好的回收率值，并且还可以作为一种智能设备来研究抗菌剂对大肠杆菌 O157:H7 的作用。
