A Non-label Electrochemical Aptasensor Based on Cu Metal–Organic Framework to Measure Aflatoxin B1 in Wheat Flour

• Published in: Food analytical methods 2022, Vol.15 (1), p.192-202
• Main Authors: Jahangiri–Dehaghani, Fahime, Zare, Hamid R., Shekari, Zahra
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Food Science; Microbiology
• ISSN: 1936-9751; 1936-976X
• DOI: 10.1007/s12161-021-02109-x

Aflatoxin B1 (AFB 1 ) is an important indicator in food safety assessment. In the present study, a non-label electrochemical aptasensor based on the Cu metal–organic framework (CuMOF) was fabricated to measure AFB 1 . The CuMOF was synthesized with a simple method and used to modify glassy carbon electrode (GCE). The field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) methods were used to describe the morphology, structure, and size of the CuMOF. It is established that the CuMOF with a large surface area played an important role as a unique substrate to immobilize AFB 1 aptamer. The fabricating stages of the aptasensor were followed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) using ferri/ferrocyanide as a redox probe. The results indicate that under optimal conditions, the aptamer-AFB 1 interaction increases the resistance to electron transfer between them. Through an EIS method, the linear range of 1.0 × 10 −3 to 200.0 ng/mL and detection limit of 8.3 × 10 −4  ng/mL were obtained for quantitative determination of AFB 1 at the aptasensor surface. In addition, the proposed aptasensor has acceptable reproducibility, repeatability, and stability to determine AFB 1 . Finally, this method has been successfully used for the analysis of AFB 1 in wheat flour samples.