Construction and characterization of platinum and gold electrodes with total structural diameters of 1-2 nm is described. These small voltammetric probes have been constructed by direct electroreduction of noble metals onto the tips of etched carbon fiber microdisk electrodes. Voltammetry, electron microscopy, energy-dispersive X-ray analysis, and pulsed amperometric detection have been used to characterize these electrodes. Dopamine concentrations have been determined over a range of 10-4-10-3 M in a biological buffer system which contains 25 mM glucose, a compound known to adsorb strongly to electrodes. Amperometric monitoring at a constant potential with these small electrodes results in signal decay of 20-40% in a 10-min experiment. Pulsed amperometric detection minimizes electrode fouling, resulting in 5% or less signal decay over the same 10-min period.
All Science Journal Classification (ASJC) codes
- Analytical Chemistry