An effective electrical sensing scheme using AC electrothermal flow on a biosensor platform based on a carbon nanotube network

We report a simple and efficient electrical sensing scheme that can be used to overcome the “diffusion limit” of affinity-basedbiosensors by incorporating the structural advantage of a concentricelectrodebiosensor platform and the microstirring effect ofAC electrothermal flow (ACEF). To prove the effect of ACEF on thebiosensor performance, we performed both simulations and experiments for the detection of cardiac troponin-I, which is a biomarker for acute myocardial infarction. The finite element simulation results indicate thatAC bias to theelectrode (which has a concentric structure in our device) can induce fast convection flow, which facilitates the transport of the target molecules to the binding region located between the twoelectrodes. In our device, the channel region made of acarbon nanotube network decorated with gold nanoparticles, which act as the attaching sites of the probe molecules, is used as a highly sensitive electrical channel. We find that the electrical sensing method exhibited extremely fast sensing speeds compared with those under no bias (diffusion-limited) conditions.

Source: Applied Physics Letters - November 28, 2016 Category: Physics Authors: Won Cheol Lee, Hoseok Lee, Jaeheung Lim and Young June Park Source Type: research