Nanocoax-Based Electrochemical Sensor

作者：Rizal Binod; Archibald Michelle M; Connolly Timothy; Shepard Stephen; Burns Michael J; Chiles Thomas C; Naughton Michael J^*

来源：Analytical Chemistry, 2013, 85(21): 10040-10044.

DOI：10.1021/ac402441x

We have used a facile polymer imprint process to fabricate a three-dimensional electrochemical nanosensor, the sensitivity of which is two decades higher than that of planar controls. The device is composed of an array of vertically oriented nanoscale coaxial electrodes, with the coax cores and shields serving as integrated working and counter electrodes, respectively, each with a nanoscale separation gap (coax annulus width). Arrays of similar to 10(6) devices per square millimeter were prepared with different gaps, with smaller gaps yielding higher sensitivity. A coax-based sensor with a 100 nm gap was found to have sensitivity 90 times greater than that of a planar sensor control, which had conventional millimeter-scale electrode gap spacing. We suggest that this enhancement is due to the combination of rapid diffusion of molecules between the closely spaced electrodes and the large number of nanoscale electrochemical cells operating in parallel, both of which enhance current per unit surface area compared to planar or other nanostructured devices.

• 出版日期2013-11-5