Label-Free and Redox Markers-Based Electrochemical Aptasensors for Aflatoxin M1 Detection

Sensors

Stefanos Karapetis¹  Tibor Hianik¹  Dimitrios Nikolelis² 

[1] Department of Nuclear Physics and Biophysics, Comenius University, Mlynska dolina F1, 842 48 Bratislava, Slovakia;Laboratory of Environmental Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis-Kouponia, 157 71 Athens, Greece;

关键词: biosensors;    aflatoxin M1;    aptasensors;    electrochemical impedance spectroscopy;    differential pulse voltammetry;   

DOI  :  10.3390/s18124218

来源: DOAJ

【 摘 要 】

We performed a comparative analysis of the sensitivity of aptamer-based biosensors for detection mycotoxin aflatoxin M₁ (AFM1) depending on the method of immobilization of DNA aptamers and method of the detection. Label-free electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) for ferrocene labeled neutravidin layers were used for this purpose. Amino-modified DNA aptamers have been immobilized at the surface of polyamidoamine dendrimers (PAMAM) of fourth generation (G4) or biotin-modified aptamers were immobilized at the neutravidin layer chemisorbed at gold surface. In the first case the limit of detection (LOD) has been determined as 8.47 ng/L. In the second approach the LOD was similar 8.62 ng/L, which is below of allowable limits of AFM1 in milk and milk products. The aptasensors were validated in a spiked milk samples with good recovery better than 78%. Comparative analysis of the sensitivity of immuno- and aptasensors was also performed and showed comparable sensitivity.

【 授权许可】

Unknown