Electrochemical switching with a DNA aptamer-based electrochemical sensor.

The present study was focused on the application of NH2-functionalized Fe3O4/gold nanoparticles (Fe3O4/AuNPs)-decorated carbon nanotubes (CNTs) in the development of electrochemical sensor for bisphenol A (BPA) detection. After the nanocomposite synthesis and its characterization, the optimization of the measurement conditions and working parameters of sensors were evaluated. Aminated detection probe (DNA aptamer) was surface confined on the NH2-functionalized Fe3O4/AuNPs surface using glutaraldehyde as a linker. The constructed nanoaptasensor incorporated the advantages of the neatly deposited Fe3O4/AuNPs and the covalent attachment of the detection probe at the surface of sensing interface. The results revealed that BPA could be detected in a wide linear range from 1 to 600nM with a low detection limit down to 300pM. Moreover, the resultant aptasensor exhibited good specificity, stability and reproducibility, indicating that the present strategy was promising for broad potential application in clinic assay.