title: Hetero-enzyme-based two-round signal amplification strategy for trace detection of aflatoxin B1 using an electrochemical aptasensor.
abstract: An electrochemical aptasensor for trace detection of aflatoxin B1 (AFB1) was developed by using an aptamer as the recognition unit while adopting the telomerase and EXO III based two-round signal amplification strategy as the signal enhancement units. The telomerase amplification was used to elongate the ssDNA probes on the surface of gold nanoparticles, by which the signal response range of the signal-off model electrochemical aptasensor could be correspondingly enlarged. Then, the EXO III amplification was used to hydrolyze the 3'-end of the dsDNA after the recognition of target AFB1, which caused the release of bounded AFB1 into the sensing system, where it participated in the next recognition-sensing cycle. With this two-round signal amplified electrochemical aptasensor, target AFB1 was successfully measured at trace concentrations with excellent detection limit of 0.6*10(-4)ppt and satisfied specificity due to the excellent affinity of the aptamer against AFB1. Based on this designed two-round signal amplification strategy, both the sensing range and detection limit were greatly improved. This proposed ultrasensitive electrochemical aptasensor method was also validated by comparison with the classic instrumental methods. Importantly, this hetero-enzyme based two-round signal amplified electrochemical aptasensor offers a great promising protocol for ultrasensitive detection of AFB1 and other mycotoxins by replacing the core recognition sequence of the aptamer.
authors.affiliation: School of Biotechnology and Food Engineering, Anhui Provincial Key Lab of Functional Materials and Devices, Hefei University of Technology, Hefei 23009, China.
authors.forename: Wanli
authors.initials: W
authors.lastname: Zheng
authors.affiliation: School of Biotechnology and Food Engineering, Anhui Provincial Key Lab of Functional Materials and Devices, Hefei University of Technology, Hefei 23009, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Teng
authors.affiliation: School of Biotechnology and Food Engineering, Anhui Provincial Key Lab of Functional Materials and Devices, Hefei University of Technology, Hefei 23009, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Cheng
authors.affiliation: School of Biotechnology and Food Engineering, Anhui Provincial Key Lab of Functional Materials and Devices, Hefei University of Technology, Hefei 23009, China.
authors.forename: Yingwang
authors.initials: Y
authors.lastname: Ye
authors.affiliation: School of Biotechnology and Food Engineering, Anhui Provincial Key Lab of Functional Materials and Devices, Hefei University of Technology, Hefei 23009, China.
authors.forename: Daodong
authors.initials: D
authors.lastname: Pan
authors.affiliation: School of Biotechnology and Food Engineering, Anhui Provincial Key Lab of Functional Materials and Devices, Hefei University of Technology, Hefei 23009, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Wu
authors.affiliation: Jiangsu Entry-Exit Inspection and Quarantine Bureau, Nanjing 200002, China. Electronic address: xuef1@jsciq.gov.cn.
authors.forename: Feng
authors.initials: F
authors.lastname: Xue
authors.affiliation: Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58102, USA.
authors.forename: Guodong
authors.initials: G
authors.lastname: Liu
authors.affiliation: School of Biotechnology and Food Engineering, Anhui Provincial Key Lab of Functional Materials and Devices, Hefei University of Technology, Hefei 23009, China. Electronic address: chenweishnu@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
mesh_terms: D016604:Aflatoxin B1 / Q000737:chemistry / Q000302:isolation & purification*; D052157:Aptamers, Nucleotide / Q000737:chemistry; D015374:Biosensing Techniques; D004247:DNA / Q000737:chemistry; D055664:Electrochemical Techniques; D005090:Exodeoxyribonucleases / Q000737:chemistry; D006046:Gold; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D019098:Telomerase / Q000737:chemistry
chemical_list: D052157:Aptamers, Nucleotide; D006046:Gold; D004247:DNA; D016604:Aflatoxin B1; D019098:Telomerase; D005090:Exodeoxyribonucleases; C020133:exodeoxyribonuclease III
keywords: Aflatoxin B1; Aptasensor; Electrochemical; Gold nanoparticle; Signal amplification