Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture, China Agricultural University, Beijing 100083, China.
Key Laboratory of Modern Precision Agriculture System Integration Research, Ministry of Education, China Agricultural University, Beijing 100083, China.
Biosens Bioelectron. 2019 Jan 15;124-125:143-149. doi: 10.1016/j.bios.2018.10.006. Epub 2018 Oct 11.
We intended to develop a novel biosensor using gold nanoparticles (AuNPs) for indicating different concentrations of E. coli O157:H7 and smart phone imaging APP for monitoring color change of the AuNPs. The magnetic nanoparticles (MNPs) modified with the capture antibodies and the polystyrene microspheres (PSs) modified with the detection antibodies and the catalases were simultaneously used to react with the target bacteria in the first mixing channel of the microfluidic chip, and hydrogen peroxide was injected and catalyzed by the catalases on the MNP-bacteria-PS complexes. After the mixture of the AuNPs and the crosslinking agents were injected to react with the catalysate in the second mixing channel and incubated in the detection chamber, the aggregation of the AuNPs was triggered through the crosslinking agents, resulting in the color of the AuNPs changing from blue to red. Finally, the color was measured using the smart phone imaging APP to determine the amount of the bacteria. This biosensor exhibited a good specificity and sensitivity for detection of E. coli O157:H7 in chicken samples with a lower detection limit of 50 CFU/mL.
我们旨在开发一种新型生物传感器，该传感器使用金纳米粒子 (AuNPs) 来指示不同浓度的大肠杆菌 O157:H7，并用智能手机成像 APP 监测 AuNPs 的颜色变化。修饰有捕获抗体的磁性纳米粒子 (MNPs) 和修饰有检测抗体和过氧化物酶的聚苯乙烯微球 (PSs) 同时用于在微流控芯片的第一混合通道中与靶细菌反应，并将过氧化氢注入并由 MNPs-细菌-PS 复合物上的过氧化物酶催化。将 AuNPs 和交联剂的混合物注入第二混合通道中与酶促产物反应，并在检测室中孵育后，交联剂引发 AuNPs 的聚集，导致 AuNPs 的颜色从蓝色变为红色。最后，使用智能手机成像 APP 测量颜色以确定细菌的数量。该生物传感器对鸡肉样品中的大肠杆菌 O157:H7 具有良好的特异性和灵敏度，检测限低至 50 CFU/mL。
