Electrochemistry through glass.
In this Article we have used new approaches to investigate a well-known chemical process, the propagation of electrochemical signals through a thin glass membrane. This process, which has been extensively studied over the last century, is the basis of the response of a potentiometric glass pH sensor; however, no amperometric glass sensors have yet been reported because of its high ohmic resistance. Voltammetry at nanoelectrodes has revealed that water molecules can diffuse through nanometre-thick layers of dry glass and undergo oxidation/reduction at the buried platinum surface. After soaking for a few hours in an aqueous solution, voltammetric waves of other redox couples, such as Ru(NH(3))(6)(3+/2+), could also be obtained at the glass-covered platinum nanoelectrodes. This behaviour suggests that the nanometre-thick insulating glass sheath surrounding the platinum core can be largely converted to hydrated gel, and electrochemical processes occur at the platinum/hydrogel interface. Potential applications range from use in nanometre-sized solid-state pH probes and determination of the water content in organic solvents to glass-modified voltammetric sensors and electrocatalysts.
Velmurugan
Jeyavel
J
Department of Chemistry and Biochemistry, Queens College-CUNY, Flushing, New York 11367, USA.
Zhan
Dongping
D
Mirkin
Michael V
MV
D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D005898:Glass / Q000737:chemistry*; D020100:Hydrogels; D053768:Metal Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology; D010084:Oxidation-Reduction; D010984:Platinum / Q000737:chemistry*; D013499:Surface Properties
D020100:Hydrogels; D010984:Platinum; D003300:Copper