AbstractThe authors describe a rapid colorimetric assay for Listeria monocytogenes (L. monocytogenes) based on the o-phenylenediamine-mediated deaggregation of gold nanoparticles. Silver nanoclusters are used as an artificial enzyme that can oxidize o-phenylenediamine to form o-benzoquinone diamine. Aptamer and IgY antibodies were chosen to conjugate with magnetic beads and silver nanoclusters, respectively, which can recognize and bind L. monocytogenes at different specific binding sites. This results in the disassembly of colloidal gold nanoparticles which is accompanied by a color change from blue to red, with peaks at 730 and 525 nm, respectively. The method allows L. monocytogenes to be colorimetrically determined in the 10 to 106 cfu·mL−1 concentration range without pre-enrichment, and the limit of detection is as low as 10 cfu·mL−1. Recoveries ranging from 97.4 to 101.3% are found when analyzing spiked food samples. The assay is rapid, sensitive and specific. Graphical abstractSchematic illustration of a colorimetric method for detection of L. monocytogenes based on silver nanoclusters-catalyzed oxidation of OPD and de-aggregation of GNPs. A color change from blue to red can be observed and correlated to the concentration of L. monocytogenes.

中文翻译：

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通过使用核心金纳米粒子、银纳米簇作为氧化酶模拟物和适体结合的磁性纳米粒子对单核细胞增生李斯特菌进行比色免疫分析

摘要作者描述了一种基于邻苯二胺介导的金纳米粒子解聚作用的单核细胞增生李斯特菌 (L. monocytogenes) 的快速比色分析。银纳米团簇用作人工酶，可以氧化邻苯二胺形成邻苯醌二胺。选择适体和 IgY 抗体分别与磁珠和银纳米团簇结合，它们可以在不同的特异性结合位点识别和结合单核细胞增生李斯特菌。这导致胶体金纳米粒子的分解，伴随着颜色从蓝色变为红色，峰值分别位于 730 和 525 nm。该方法允许在 10 至 106 cfu·mL-1 浓度范围内比色测定单核细胞增生李斯特菌，无需预富集，检测限低至 10 cfu·mL-1。分析加标食品样品时发现回收率在 97.4% 到 101.3% 之间。该测定是快速、灵敏和特异的。基于银纳米团簇催化 OPD 氧化和 GNP 解聚的单核细胞增生李斯特菌比色法检测示意图。可以观察到颜色从蓝色变为红色，并与单核细胞增生李斯特氏菌的浓度相关。