title: A structure-switchable aptasensor for aflatoxin B1 detection based on assembly of an aptamer/split DNAzyme.
abstract: An ultrasensitive, colorimetric and homogeneous strategy for aflatoxin B1 (AFB1) detection, which uses a DNA aptamer and two split DNAzyme halves, has been developed. Split halves of a hemin-binding DNAzymes is combined with an AFB1 aptamer to generate a homogeneous colorimetric sensor that undergoes an AFB1 induced DNA structural change. In the absence of AFB1, the split probes have peroxidase mimicking DNAzyme activity associated with catalysis of a color change reaction. Specific recognition of AFB1 by the aptamer component leads to structural deformation of the aptamer-DNAzyme complex, which causes splitting of the DNAzyme halves and a reduction in peroxidase mimicking activity. Therefore, a decrease of colorimetric signal arising from the catalytic process takes place upon in the presence of AFB1 in a concentration dependent manner in the 0.1-1.0 × 10(4) ng/mL range and with a colorimetric detection limit of 0.1 ng/mL. The new assay system exhibits high selectivity for AFB1 over other mycotoxins and can be employed detect the presence of AFB1 in ground corn samples. Overall, the strategy should serve as the basis for the development of rapid, simple and low-cost methods for detection of mycotoxins.
authors: Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Gwangju 500-712, Republic of Korea.
authors: Youngung
authors: Y
authors: Seok
authors: Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Gwangju 500-712, Republic of Korea.
authors: Ju-Young
authors: JY
authors: Byun
authors: Food Analysis Research Team, Industry Service Research Center, World Institute of Kimchi an Annex of Korea Food Research Institute, 86, Kimchi-ro, Nam-gu, Gwangju, Republic of Korea.
authors: Won-Bo
authors: WB
authors: Shim
authors: Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Gwangju 500-712, Republic of Korea; Advanced Photonics Research Institute, Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Gwangju 500-712, Republic of Korea. Electronic address: mkim@gist.ac.kr.
authors: Min-Gon
authors: MG
authors: Kim
mesh_terms: D016604:Aflatoxin B1 / Q000032:analysis*; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D003124:Colorimetry / Q000379:methods; D021881:DNA, Catalytic / Q000737:chemistry*; D054856:G-Quadruplexes; D057230:Limit of Detection; D003313:Zea mays / Q000382:microbiology*
chemical_list: D052157:Aptamers, Nucleotide; D021881:DNA, Catalytic; D016604:Aflatoxin B1
keywords: Aflatoxin B1; Aptamer; Colorimetric; Mycotoxin; Split DNAzyme