Steady-state voltammetric response of the nanopore electrode.
The steady-state voltammetric response of the truncated conical-shaped glass nanopore electrode is presented. Analytical theory, finite-element simulations, and experimental measurement of the diffusive flux of a redox molecule through the pore orifice demonstrate that the steady-state current decreases rapidly as the pore depth increases and then asymptotically approaches a constant value when the pore depth is approximately 50x larger than the pore orifice. The asymptotic limit of the steady-state current is only a function of the pore orifice radius and the cone angle of the pore and has a finite value for all cone angles greater than zero. Experimental confirmation of the predicted dependence on pore depth is obtained using nanopore electrodes with 100-1000 nm orifice radii, by measuring the steady-state voltammetric current corresponding to the oxidation of ferrocene in acetonitrile solutions containing an excess of supporting electrolyte.
Zhang
Bo
B
Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, USA.
Zhang
Yanhui
Y
White
Henry S
HS
D016494:Computer Security; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D005296:Ferrous Compounds / Q000737:chemistry; D020342:Finite Element Analysis; D000075163:Metallocenes; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000737:chemistry*; D010084:Oxidation-Reduction
D005296:Ferrous Compounds; D000075163:Metallocenes; C004998:ferrocene