title: Label-free colorimetric aptasensor for sensitive detection of ochratoxin A utilizing hybridization chain reaction.
abstract: The combination of high selectivity of aptamer with the peroxidase-mimicking property of DNAzyme has presented considerable opportunities for designing colorimetric aptasensor for detection of ochratoxin A (OTA). The activities of both aptamer (as biorecognition element) and DNAzyme (as signal amplification element) are blocked via base pairing in the hairpin structure. Hybridization chain reaction (HCR) between two hairpin DNAs was employed to further improve the sensitivity of this method. The presence of OTA triggers the opening of the hairpin structure and the beginning of HCR, which results in the release of many DNAzyme, and generates enhanced colorimetric signals, which is correlated to the amounts of OTA with linear range between 0.01 to 0.32 nM, and the limit of detection is 0.01 nM under optimal conditions. OTA in yellow rice wine and wheat flour samples was also detected using this method. We demonstrate that a new colorimetric method for the detection of OTA has been established, which is simple, easy to conduct, label-free, sensitive, high throughput, and cost-saving.
authors: School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China.
authors: Chengke
authors: C
authors: Wang
authors: Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
authors: Xiaoya
authors: X
authors: Dong
authors: Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
authors: Qian
authors: Q
authors: Liu
authors: Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China. Electronic address: wangkun@ujs.edu.cn.
authors: Kun
authors: K
authors: Wang
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000378:metabolism; D015374:Biosensing Techniques; D003124:Colorimetry; D021881:DNA, Catalytic / Q000737:chemistry / Q000378:metabolism; D005433:Flour / Q000032:analysis; D009693:Nucleic Acid Hybridization; D009793:Ochratoxins / Q000032:analysis*; D014920:Wine / Q000032:analysis
chemical_list: D052157:Aptamers, Nucleotide; D021881:DNA, Catalytic; D009793:Ochratoxins; C025589:ochratoxin A
keywords: Aptamer; Colorimetric method; Hybridization chain reaction; Ochratoxin A