Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing, 100083, China.
Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing, 100083, China; Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology & Business University, Beijing, 100048, China.
Anal Chim Acta. 2022 Jul 25;1218:339850. doi: 10.1016/j.aca.2022.339850. Epub 2022 May 25.
Rapid and sensitive screening of pathogens is a key to prevent the outbreak of foodborne illnesses. Herein, a new colorimetric immunoassay was proposed based on the release of Ag ions from AgNPs and the inhibition of PtNPs, and its supporting microfluidic platform was developed to automatically perform the whole bacterial detection procedure using Raspberry Pi and smartphone App. First, the immune AgNPs and magnetic nanobeads (MNBs) were used to conjugate with Salmonella typhimurium. Then, HO was used to etch the AgNPs for release Ag ions. Finally, the colorimetric signal was greatly diminished because of the specific and efficient inhibition of Ag toward the peroxidase-like activity of the PtNPs. This colorimetric immunoassay showed a good specificity and an ultralow detection limit of 16.8 CFU/mL, which was about 3 orders of magnitude improvement compared with conventional ELISA, and the averaged recovery for the spiked chicken samples was 95.6%. The combination of this immunoassay with this microfluidic platform might be promising for rapid and sensitive screening of foodborne pathogens to ensure food safety.
快速灵敏地筛选病原体是预防食源性疾病爆发的关键。在此，我们提出了一种基于 AgNPs 释放 Ag 离子和 PtNPs 抑制的比色免疫分析方法，并开发了配套的微流控平台，使用树莓派和智能手机应用程序自动执行整个细菌检测过程。首先，免疫 AgNPs 和磁性纳米珠（MNBs）与鼠伤寒沙门氏菌结合。然后，HO 用于刻蚀 AgNPs 以释放 Ag 离子。最后，由于 Ag 对 PtNPs 的过氧化物酶样活性具有特异性和高效抑制作用，比色信号大大减弱。该比色免疫分析具有良好的特异性和超低的检测限（16.8 CFU/mL），与传统 ELISA 相比提高了约 3 个数量级，对鸡肉样品的平均回收率为 95.6%。这种免疫分析与微流控平台的结合可能有望用于快速灵敏地筛选食源性病原体，以确保食品安全。
