DNA Electrochemical Aptasensor for Detecting Fumonisins B sub(1) Based on Graphene and Thionine Nanocomposite

• Published in: Electroanalysis (New York, N.Y.) N.Y.), 2015-05, Vol.27 (5), p.1097-1103
• Main Authors: Shi, Zhi-Yu, Zheng, Ya-Ting, Zhang, Hao-Bo, He, Cheng-Hua, Wu, Wen-Da, Zhang, Hai-Bin
• Format: Article
• Language: English
• Subjects: Deoxyribonucleic acid; Electrical resistivity; Electrodes; Graphene; Nanoparticles; Nanostructure; Resistivity; Stacking
• ISSN: 1040-0397; 1521-4109
• DOI: 10.1002/elan.201400504

In this paper, a novel aptasensor was designed by with the dual amplification of Au nanoparticles (AuNPs) and graphene/thionine nanocomposites (GS-TH) for sensitive determination of fumonisins B sub(1) (FB sub(1)). AuNPs is modified at the electrode surface to increase the electrical conductivity and fabricate specific recognition interface for FB sub(1) through the hybridization of capture DNA and its aptamer. Large number of TH molecules were loaded at the surface of graphene sheet to served as electrochemical probe and increase its electrochemical signal due to the excellent conductivity and large surface area of graphene sheet. This type of nanocomposites is then assembled to the single strand section of FB sub(1) aptamer at electrode surface by pi - pi stacking interactions between them, leading to an enhanced electrochemical signal. After the specific combination between FB sub(1) aptamer and its target (FB sub(1)) in solution, GS-TH was released from electrode surface, resulting in a decreased electrochemical signal. The result demonstrated that the decreased currents were proportional to the FB sub(1) concentration in the range of 1-10 super(6)pg/mL with a detection limit of 1pg/mL. Besides, the developed aptasensor was also applied successfully for the determination of FB sub(1) in feed samples. The result shows this aptasensor has a higher sensitivity and selectivity.