2008 NSTI Nanotechnology Conference and Trade Show - Nanotech 2008 - 11th Annual

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Dopamine detection using diamond nano-ridge structures

S. Raina, W.P. Kang, J.L. Davidson
Vanderbilt University, US

Keywords:
diamond, sensor

Abstract:
This paper reports the detection of dopamine (DA), an important catecholamine neurotransmitter, using a novel planar electrode consisting of diamond nano-ridge structures grown on a silicon substrate. The diamond nano-ridges were grown in a 1.5kW, 2.45 GHz ASTEX MPECVD machine using H2/CH4/N2 gases in the plasma. Detail fabrication of the electrode will be described. The detection of DA was done in a 3-electrode flat-cell using Ag/AgCl, platinum, and the diamond nano-ridges as the reference, counter, and working electrode, respectively. The nanodiamond electrode shows a wide working potential window of ~3V over a wide scan rates. The cyclic voltammogram (CV) obtained from 1mM DA in 0.1M PBS with pH 7at scan rate of 100mV/s shows distinct redox peaks of the analyte species. The DA peak-oxidation current increases linearly with dopamine concentration. The graph for Scan Rate versus Time(s) for 1mM DA at different scan rates shows linear relationship, indicating that planar diffusion is the dominant form of mass transport. One step chronocoulometry experiments were also done to calculate the electroactive area of the sensing electrode. The ability to detect bioanalyte without the need of functionalization or modification of the electrode surface is realized. Detail experimental data and characterization will be presented.


Nanotech 2008 Conference Program Abstract