Target-responsive aptamer-cross-linked hydrogel sensors for the visual quantitative detection of aflatoxin B1 using exonuclease I-Triggered target cyclic amplification

Mengyao Zheng; Hongmei Liu; Jin Ye; Baoxia Ni; Yanli Xie; Songxue Wang

doi:10.1016/j.fochx.2022.100395

Target-responsive aptamer-cross-linked hydrogel sensors for the visual quantitative detection of aflatoxin B₁ using exonuclease I-Triggered target cyclic amplification

Food Chem X. 2022 Jul 16:15:100395. doi: 10.1016/j.fochx.2022.100395. eCollection 2022 Oct 30.

Authors

Mengyao Zheng^{1

2}, Hongmei Liu², Jin Ye^{2

3

4}, Baoxia Ni², Yanli Xie¹, Songxue Wang^{1

2}

Affiliations

¹ College of Food Science and Engineering, Henan University of Technology, Zhengzhou 450001, China.
² Academy of National Food and Strategic Reserves Administration, Beijing 102600, China.
³ Key Laboratory of Grain Information Processing and Control (Henan University of Technology), Ministry of Education, Zhengzhou 450001, China.
⁴ Henan Key Laboratory of Grain Photoelectric Detection and Control, (Henan University of Technology), Zhengzhou 450001, China.

Abstract

For the on-site detection of aflatoxin B₁ (AFB₁), a DNA hydrogel was prepared as a biosensor substrate, while an AFB₁ aptamer was used as the recognition element. An AFB₁-responsive aptamer-cross-linked hydrogel sensor was constructed using an enzyme-linked signal amplification strategy; AFB₁ binds competitively to the aptamer, causing the hydrogel to undergo cleavage and release horseradish peroxidase (HRP). The addition of exonuclease I (ExoI) to the hydrogel causes the release of AFB₁ from the aptamer, promoting additional hydrogel cleavage to release more HRP, ultimately catalysing the reaction between 3,3',5,5'-tetramethylbenzidine and H₂O₂. The hydrogel sensor exhibited an outstanding sensitivity (limit of detection, 4.93 nM; dynamic range, 0-500 nM), and its selectivity towards seven other mycotoxins was confirmed. The feasibility and reliability were verified by measuring the AFB₁ levels in peanut oil (recoveries, 89.59-95.66 %; relative standard deviation, <7%); the obtained results were comparable to those obtained by UPLC-HRMS.

Keywords: 3,3′,5,5′-tetramethylbenzidine (TMB, PubChem CID: 41206); AFB1; Aflatoxin B2 (AFB2,PubChem CID: 2724360); Aflatoxin G1 (AFG1,PubChem CID: 14421); Agarose (PubChem CID: 11966311); Ammoniumpersulfate (APS, PubChem CID: 62648); Aptamer; Enzyme cascade; Fumonisin B1 (FB1,PubChem CID: 2733487); H2O2 (PubChem CID: 784); HRP (PubChem CID: 9865515); Hydrogel; N,N,N′,N′-tetramethylethylenediamine (TEMED, PubChem CID: 8037; T-2 toxin(T-2, PubChem CID: 5284461); Visual detection; Zearalenone (ZEN, PubChem CID: 5281576); aflatoxin B1 (AFB1,PubChem CID: 186907); and Aflatoxin M1 (AFM1,PubChem CID: 15558498); deoxynivalenol (DON, PubChem CID: 40024).