Highly sensitive colorimetric aptasensor for ochratoxin A detection based on enzyme-encapsulated liposome.

Journal: Analytica chimica acta
PMID: 29306417

Abstract

A simple, low-cost, and sensitive liposome-based colorimetric aptasensor has been developed to detect ochratoxin A (OTA). Specifically, a dumbbell-shaped probe was designed, including magnetic beads (MBs), double-stranded DNA (dsDNA), and enzyme-encapsulated liposome. The dsDNA formed by the hybridization between OTA aptamer and its complementary probe. And the dsDNA was used to contact the MBs and the enzyme-encapsulated liposome. In the presence of OTA, the aptamer preferred to combine with OTA to form G-quadruplex, resulting in the release of the detection probe and the enzyme-encapsulated liposome. Each liposome contained a large amount of HRP. Thus, when the liposome was lysed by adding the mixed solution of 3,3',5,5'-tetramethylbenzidine (TMB) and HO, a large number of HRP were released. HRP could catalyze the HO-mediated oxidation of TMB and hence resulted in the color change from colorless to blue with the OTA concentration varying, and this variation can be observed by naked eyes easily. The result showed that the absorption intensity at 652 nm enhanced with the increase of OTA concentration ranging from 0.05 to 2.0 ng mL, and the limit of detection was calculated to be 0.023 ng mL (S/N = 3). The developed colorimetric aptasensor has been applied to detect OTA concentration in corn samples with satisfied results.

Authors

  • Cuiying Lin
    MOE Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
  • Huixia Zheng
    MOE Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
  • Mi Sun
    Key Laboratory of Sustainable Development of Polar Fishery, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China. sunmi@ysfri.ac.cn.
  • Yajuan Guo
    MOE Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
  • Fang Luo
    MOE Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China; College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian 350116, China. Electronic address: luofang0812@163.com.
  • Longhua Guo
    MOE Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
  • Bin Qiu
    MOE Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
  • Zhenyu Lin
    MOE Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China. Electronic address: zylin@fzu.edu.cn.
  • Guonan Chen
    MOE Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.

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