College of Food Science and Engineering, Northwest A&F University, Yangling 712100, Shaanxi, China.
College of Food Science and Engineering, Northwest A&F University, Yangling 712100, Shaanxi, China.
J Hazard Mater. 2023 Feb 5;443(Pt A):130157. doi: 10.1016/j.jhazmat.2022.130157. Epub 2022 Oct 13.
Rapid and sensitive detection of bacterial pathogens present in food and environmental samples is of crucial importance to ensure human health and safety. Here, we present a one-step label-free colorimetric strategy based on M13 bacteriophage-displayed nanobody (phage-Nb) derived from camelid heavy-chain antibodies specific to Vibrio parahaemolyticus (V. parahaemolyticus). The thiolation of phage-Nb (Phage-Nb-SH) on pVIII shell proteins induces the aggregation of gold nanoparticles (AuNPs), whereas the specific interaction between nanobody and bacteria prevents the aggregation of AuNPs, resulting in visible color change due to alteration of surface plasmon resonance properties. Based on this phenomenon, a simple and sensitive colorimetric immunosensor for V. parahaemolyticus was developed. The assay can be accomplished within 100 min, and exhibits a visual detection limit of 10 cfu/mL and a quantitative detection limit of 10 cfu/mL, with no cross-reactivity towards other bacterial species. This strategy takes full advantages of both the high specificity of phage-Nbs and the optical properties of AuNPs, enabling simple and rapid detection of bacterial pathogens.
快速灵敏地检测食品和环境样本中的细菌病原体对于确保人类健康和安全至关重要。在这里，我们提出了一种基于 M13 噬菌体展示纳米抗体（噬菌体-Nb）的一步法无标记比色策略，该纳米抗体源自针对副溶血性弧菌（V. parahaemolyticus）的骆驼重链抗体。噬菌体-Nb（Phage-Nb-SH）在 pVIII 壳蛋白上的巯基化诱导金纳米颗粒（AuNPs）的聚集，而纳米抗体与细菌之间的特异性相互作用阻止了 AuNPs 的聚集，从而由于表面等离子体共振特性的改变导致可见颜色变化。基于此现象，开发了一种用于副溶血性弧菌的简单灵敏的比色免疫传感器。该测定可在 100 分钟内完成，具有 10 cfu/mL 的目视检测限和 10 cfu/mL 的定量检测限，对其他细菌物种无交叉反应性。该策略充分利用了噬菌体-Nb 的高特异性和 AuNPs 的光学性质，实现了对细菌病原体的简单快速检测。
