食品科学 ›› 2011, Vol. 32 ›› Issue (8): 177-181.doi: 10.7506/spkx1002-6630-201108040

• 分析检测 • 上一篇    下一篇

基于生物条形码探针和金纳米颗粒的大肠杆菌O157:H7检测

蒲小平,杨海麟,周楠迪*   

  1. 江南大学生物工程学院,工业生物技术教育部重点实验室
  • 出版日期:2011-04-25 发布日期:2011-04-12
  • 基金资助:
    国家自然科学基金青年项目(20805020);教育部科学技术研究重点项目(109079); 食品科学与技术国家重点实验室开放课题(SKLF-KF-200809)

Detection of Escherichia coli O157:H7 Based on Bio-Bar Codes Probes and Gold Nanoparticles

PU Xiao-ping,YANG Hai-lin,ZHOU Nan-di*   

  1. Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
  • Online:2011-04-25 Published:2011-04-12

摘要: 建立一种基于生物条形码探针和金纳米颗粒(gold nanoparticles,AuNPs)对致病性大肠杆菌O157:H7检测的新方法。用生物功能化的磁性纳米颗粒(magnetic nanoparticles,MNPs)和AuNPs与目标物大肠杆菌O157:H7进行免疫反应,形成MNPs/目标物/AuNPs“三明治”式复合体。利用去杂交将AuNPs上标记的条形码DNA释放出来,通过DNA探针杂交条形码DNA引起AuNPs颜色变化来确定大肠杆菌O157:H7的存在,这种颜色变化很容易用裸眼观察到并且可以通过紫外-可见吸收光谱定量分析,该方法在纯样品和牛奶中最低检测限为102CFU/mL,检测范围为102~106CFU/mL。应用基于生物条形码探针和AuNPs对大肠杆菌O157:H7检测具有准确、快速、操作简单的优点,为食品安全监测提供了新的方法。

关键词: 磁性纳米颗粒, 金纳米颗粒, 生物条形码, 紫外-可见分光光度法, 大肠杆菌O157:H7

Abstract: A novel assay was developed for the detection of Escherichia coli O157:H7 (E. coli O157:H7) based on bio-bar DNA and gold nanoparticles (AuNPs). The immune reaction between the target and antibodies modified on biofunctionalized magnetic nanoparticles (MNPs) or AuNPs leads to the formation of a sandwich structure of MNPs/target/AuNPs, followed by de-hybridization and release of bio-bar DNA. Due to its ability to hybridize with probe ssDNAs modified on AuNPs, bio-bar DNA could lead to aggregation and color change of AuNPs, which is readily visible with naked eyes, and can be quantified by UV-visible spectroscopy as well. The proposed method had a detection limit of about 102 CFU/mL in both pure broth culture and milk with a detection range of 102-106 CFU/mL. With the aid of bio-bar DNA and AuNPs, detection of E. coli O157: H7 in food is accurate, fast, and easy-operated, which may provide a new tool for food safety monitoring.

Key words: magnetic nanoparticles, gold nanoparticles, bio-bar codes, UV-visible spectroscopy, E. coli O157:H7

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