In order to monitor and respond rapidly to outbreaks of food-borne pathogens, establishing rapid and sensitive detection methods is becoming increasingly urgent. In this work, through the synthesis of copper-based metal-organic framework nanoparticles (Cu-MOF NPs) and functionalized with aptamers, we developed a colorimetric protocol to detect Escherichia coli. In a typical experimental procedure, aptamer 1 was immobilized onto microplate to act as capture probes. Cu-MOF NPs were synthesized and functionalized with streptavidin and biotinylated aptamer 2 to form the signal probes. In the presence of E. coli, aptamers on both capture and signal probes bind with E. coli and form a sandwich-type complex. The Cu-MOF NPs enable to catalyze the colorless peroxidase substrate to yield a colorimetric output signal. This peroxidase-like mimics-based colorimetric aptasensor showed a rapid and sensitive quantification of E. coli in the concentration range of 16~1.6 × 10⁶ cfu/mL with a limit of quantitation (LOQ) of 16 cfu/mL and limit of detection (LOD) of 2 cfu/mL. The application of the developed assay for colorimetric measuring of milk samples was evaluated with satisfactory results. The developed Cu-MOF NPs-assisted visual method can be expected as a powerful alternative and promising tool for foodborne pathogen detection and control.

为了监视食源性病原体的暴发并对之迅速做出反应，建立快速灵敏的检测方法变得越来越紧迫。在这项工作中，通过合成铜基金属-有机骨架纳米颗粒（Cu-MOF NP）并用适体功能化，我们开发了比色法来检测大肠杆菌。在典型的实验程序中，将适体1固定在微孔板上以充当捕获探针。合成了Cu-MOF NP，并用链霉亲和素和生物素化的适体2进行了功能化，以形成信号探针。在存在大肠杆菌的情况下，捕获探针和信号探针上的适体均与大肠杆菌结合并形成三明治型复合物。Cu-MOF NP能够催化无色过氧化物酶底物以产生比色输出信号。这种基于过氧化物酶的模拟物比色适体传感器可在16〜1.6 ×10 ⁶  cfu / mL的浓度范围内对大肠杆菌进行快速灵敏的定量，定量限（LOQ）为16 cfu / mL，检测限为（LOD）为2 cfu / mL。评估开发的测定法在牛奶样品的比色测量中的应用，结果令人满意。可以预期，发达的Cu-MOF NPs辅助视觉方法将成为食源性病原体检测和控制的有力替代方法和有前途的工具。