State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, PR China.
Zhejiang Rural Commercial Digital Technology Co., Ltd., Hangzhou 310016, PR China.
J Hazard Mater. 2023 Oct 5;459:132250. doi: 10.1016/j.jhazmat.2023.132250. Epub 2023 Aug 8.
Pathogenic bacteria contamination poses a major threat to human health. The detection of low-abundance bacteria in complex samples has always been a knotty problem, and high-sensitivity bacterial detection remains challenging. In this work, a novel magnetic platform with high enrichment efficiency for L. monocytogenes was developed. The magnetic platform was designed by branched polyglutamic acid-mediated indirect coupling of cefepime on magnetic nanoparticles (Cefe-PGA-MNPs), and the specific enrichment of low-abundance L. monocytogenes in real samples was achieved by an external magnet, with a capture efficiency over 90%. A controllable and highly active platinum-palladium nanozyme was synthesized and further introduced in the magnetic nanoplatform for the construction of enzymatic colorimetric biosensor. The total detection time for L. monocytogenes was within 100 min. The colorimetric signals generated by labelled nanozyme were corresponding to different concentrations of L. monocytogenes, with a limit of detection (LOD) of 3.1 × 10 CFU/mL, and high reliability and accuracy (with a recovery rate ranging from 96.5% to 116.4%) in the test of real samples. The concept of the developed method is applicable to various fields of biosensing that rely on magnetic separation platforms.
病原菌污染对人类健康构成重大威胁。在复杂样本中检测低丰度细菌一直是一个棘手的问题，而高灵敏度的细菌检测仍然具有挑战性。在这项工作中，开发了一种用于李斯特菌的新型高富集效率的磁性平台。该磁性平台是通过支化聚谷氨酸介导的头孢噻肟在磁性纳米颗粒（Cefe-PGA-MNPs）上的间接偶联设计的，通过外部磁铁实现了低丰度李斯特菌在实际样品中的特异性富集，捕获效率超过 90%。进一步在磁性纳米平台中引入了可控且高活性的铂钯纳米酶，用于构建酶比色生物传感器。李斯特菌的总检测时间在 100 分钟内。标记纳米酶产生的比色信号与不同浓度的李斯特菌相对应，李斯特菌的检测限（LOD）为 3.1×10 CFU/mL，在实际样品的测试中具有较高的可靠性和准确性（回收率范围为 96.5%至 116.4%）。所开发方法的概念适用于依赖于磁性分离平台的各种生物传感领域。
