Highly selective dengue virus detection using carbon nanotubes: Effect of pulse biasing in serum

Electrical pulse biasing was used for selective and sensitive detection in serum of a target DNA sequence (dengue fever virus-specific sequence in this study) based on a carbon nanotube network decorated with gold nano particles. A significant increase in the affinity constant (as much as 1.01×109 M-1 from the Langmuir fitting) has been obtained in addition to the enhancement in selectivity against the nonselective molecules. The physical reason of the enhancement is believed to be the physical oscillation of the probe DNA molecules caused by the applied electrical pulse trains, thereby increase in the binding chance between the probe and target DNA´s. With the technique, a wide dynamic range (10 pM-10 μM) detection of the target DNA molecules has been achieved in the serum condition.