MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
Biosens Bioelectron. 2017 May 15;91:238-245. doi: 10.1016/j.bios.2016.11.044. Epub 2016 Nov 17.
Pathogens pose a significant threat to public health worldwide. Despite many technological advances in the rapid diagnosis of pathogens, sensitive pathogen detection remains challenging because target pathogenic bacteria usually exist in complex samples at very low concentrations. Here, the construction of multivalent brush-like magnetic nanoprobes and their application for the efficient enriching of pathogens are demonstrated. Brush-like magnetic nanoprobes were constructed by modification with poly-L-lysine (PLL) onto amino-modified magnetic beads, followed by coupling of PEG (amine-PEG-COOH) to the amine sites of PLL. Subsequently, vancomycin (Van), a small-molecule antibiotic with affinity to the terminal peptide (D-alanyl-D-alanine) on the cell wall of Gram-positive bacteria, was conjugated to the carboxyl of the PEG. The use of multivalent brush-like magnetic nanoprobes (Van-PEG-PLL-MNPs) results in a high enrichment efficiency (>94%) and satisfactory purity for Listeria monocytogenes (employed as a model) within 20min, even at bacterial concentrations of only 10cfumL. Integrated with the enrichment of the Van-PEG-PLL-MNP nano-platform and electrochemiluminescence (ECL) detection, Listeria monocytogenes can be rapidly and accurately detected at levels as low as 10cfumL. The approach described herein holds great potential for realizing rapid and sensitive pathogen detection in clinical samples.
病原体对全球公共卫生构成重大威胁。尽管在病原体的快速诊断方面取得了许多技术进步，但敏感的病原体检测仍然具有挑战性，因为目标致病性细菌通常以非常低的浓度存在于复杂的样本中。在这里，展示了多价刷状磁性纳米探针的构建及其在病原体的有效富集中的应用。通过将聚-L-赖氨酸 (PLL) 修饰到氨基修饰的磁性珠上，然后将聚乙二醇 (胺-PEG-COOH) 偶联到 PLL 的胺位点上，构建了刷状磁性纳米探针。随后，将具有与革兰氏阳性菌细胞壁上末端肽 (D-丙氨酰-D-丙氨酸) 亲和力的小分子抗生素万古霉素 (Van) 偶联到 PEG 的羧基上。使用多价刷状磁性纳米探针 (Van-PEG-PLL-MNPs) 可在 20 分钟内实现对单核细胞增生李斯特菌（用作模型）的高富集效率（>94%）和令人满意的纯度，即使细菌浓度仅为 10cfu/mL 也是如此。与 Van-PEG-PLL-MNP 纳米平台的富集和电化学发光 (ECL) 检测相结合，可在低至 10cfu/mL 的水平快速准确地检测单核细胞增生李斯特菌。本文所述的方法在实现临床样本中快速、敏感的病原体检测方面具有很大的潜力。
