School of Public Health, Jilin University, Changchun, 130021, China.
The Department of Medical Insurance Management, The Second Hospital of Jilin University, Changchun, 130022, China.
Mikrochim Acta. 2018 Jul 5;185(8):360. doi: 10.1007/s00604-018-2896-1.
The 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 10 cfu·mL concentration range without pre-enrichment, and the limit of detection is as low as 10 cfu·mL. Recoveries ranging from 97.4 to 101.3% are found when analyzing spiked food samples. The assay is rapid, sensitive and specific. Graphical abstract Schematic 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.
作者描述了一种基于邻苯二胺介导的金纳米颗粒解聚集作用的李斯特菌（Listeria monocytogenes，L. monocytogenes）快速比色检测方法。银纳米簇被用作一种人工酶，可以将邻苯二胺氧化形成邻苯醌二胺。适配体和 IgY 抗体分别被选择与磁性珠和银纳米簇偶联，它们可以在不同的特异性结合位点识别和结合李斯特菌。这导致胶体金纳米颗粒的解体，伴随着颜色从蓝色变为红色的变化，分别在 730 和 525nm 处出现峰值。该方法无需预富集即可在 10 至 10cfu·mL 的浓度范围内对李斯特菌进行比色测定，检测限低至 10cfu·mL。在分析添加的食品样本时，回收率在 97.4%至 101.3%之间。该测定方法快速、灵敏且具有特异性。
