Turn-On Fluorescence Aptasensor on Magnetic Nanobeads for Aflatoxin M1 Detection Based on an Exonuclease III-Assisted Signal Amplification Strategy
Fuyuan Zhang,
Linyang Liu,
Shengnan Ni,
Jiankang Deng,
Guo-Jun Liu,
Ryan Middleton,
David W. Inglis,
Shuo Wang,
Guozhen Liu
Affiliations
Fuyuan Zhang
ARC Centre of Excellence in Nanoscale Biophotonics (CNBP), Macquarie University, North Ryde, NSW 2109, Australia
Linyang Liu
Graduate School of Biomedical Engineering, Faculty of Engineering, University of New South Wales, Sydney, NSW 2052, Australia
Shengnan Ni
International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, China
Jiankang Deng
State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology, Tianjin 300457, China
Guo-Jun Liu
Australian Nuclear Science and Technology Organization, Lucas Heights, NSW 2234, Australia
Ryan Middleton
Australian Nuclear Science and Technology Organization, Lucas Heights, NSW 2234, Australia
David W. Inglis
ARC Centre of Excellence in Nanoscale Biophotonics (CNBP), Macquarie University, North Ryde, NSW 2109, Australia
Shuo Wang
State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology, Tianjin 300457, China
Guozhen Liu
ARC Centre of Excellence in Nanoscale Biophotonics (CNBP), Macquarie University, North Ryde, NSW 2109, Australia
In order to satisfy the need for sensitive detection of Aflatoxin M1 (AFM1), we constructed a simple and signal-on fluorescence aptasensor based on an autocatalytic Exonuclease III (Exo III)-assisted signal amplification strategy. In this sensor, the DNA hybridization on magnetic nanobeads could be triggered by the target AFM1, resulting in the release of a single-stranded DNA to induce an Exo III-assisted signal amplification, in which numerous G-quadruplex structures would be produced and then associated with the fluorescent dye to generate significantly amplified fluorescence signals resulting in the increased sensitivity. Under the optimized conditions, this aptasensor was able to detect AFM1 with a practical detection limit of 9.73 ng kg−1 in milk samples. Furthermore, the prepared sensor was successfully used for detection of AFM1 in the commercially available milk samples with the recovery percentages ranging from 80.13% to 108.67%. Also, the sensor performance was evaluated by the commercial immunoassay kit with satisfactory results.
