Electrochemical Glucose Oxidation on a Platinized Platinum Electrode in Krebs‐Ringer Solution: II . Potentiostatic Studies

Abstract

The kinetics of the anodic oxidation of glucose in a calcium‐free, Krebs‐Ringer bicarbonate buffer solution at 37°C was studied with a platinized platinum rotating‐disk electrode. Potentiostatic measurements were performed over a potential range of −200 to about 200 mV vs. the saturated calomel electrode (SCE). Excellent reproducibility was achieved by activating the electrode prior to each measurement by an electrochemical pulsing procedure, The current‐time curves did not attain a steady‐state value even after several hours, suggesting that a slow deactivation of the electrode was occurring during the glucose oxidation reaction. Over a limited potential range the current decay exhibited a logarithmic dependence on time. This behavior was interpreted in terms of adsorption of an inhibiting species according to the Elovich equation. The variation of glucose oxidation rate as a function of electrode rotation rate showed that the reaction was predominantly activation controlled. Calculated values of n , the over‐all charge transfer number for glucose oxidation, were dependent upon both potential and time and ranged from about 4 to 20 under the conditions studied.

Physicochemical Determinations of Glucose in vivo

“…In polarograms with a mercury dropping electrode^ which permit quantitative measurement of oxidation and reduction processes by characteristic alterations of the current (polarographic steps), we detected no such changes, even at very high glucose concentrations. We must therefore conclude that the glucose-dependent increase of the electrode current as shown by Soeldner et al (14)(15)(16)(17)(18)(19) cannot be explained by a simple redox reaction of glucose at the electrodes.…”

Abiotic (Nonenzymatic) Implantable Biofuel Cells

“…Gluconolactone undergoes hydrolysis to form gluconic acid [14]. A number of studies showed that gluconic acid can be further oxidized, but at comparably slower reaction rates [15][16][17][18][19]. A detailed treatise on glucose electro-oxidation under different conditions is available elsewhere [20][21][22][23][24][25].…”

“…A well-known phenomenon is the gradual deactivation (poisoning) of platinum electrodes when operated for anodic glucose oxidation in neutral buffers. Commonly, this observation is attributed to the adsorption of reaction products and chemisorbed intermediates [18,19]. Generally, there is no agreement in literature regarding the nature of the poisoning species [79].…”

Entwicklung und Erprobung eines elektrokatalytischen Glucosesensors für die Diabetes-Therapie - Development and Evaluation of an Electrocatalytic Glucose Sensor for Diabetes Therapy

“…Die grundlegenden Untersuchungen zur Glucose-*^^ Messungen an m fr0#oßder$ hohe un4 ten liefert [2,9,13,15,17]. Nach diesen Untersuchungen wurde als Meßpotential für die Glucoseoxidation der Bereich um 400 mV (gegenüber H 2 rev) ausgewählt.…”