Electrochemical pretreatment of carbon fibers for in vivo electrochemistry: effects on sensitivity and response time

Abstract

Oxidative electrochemical pretreatment of carbon fibers greatly Improves their sensitivity for In vivo electrochemical detection of catecholamine species. It Is shown that the extent of the anodic potential excursion In the pretreatment Is a major factor In both the sensitivity and the response time of the resulting fiber electrode. The high sensitivity for neurotransmitter species such as dopamine appears mainly due to adsorption on the oxidized carbon fiber surface states. Practical protocols for fiber electrodes to be used In In vivo brain studies are evaluated.

Detecting Subsecond Dopamine Release with Fast-Scan Cyclic Voltammetry in Vivo

“…linearly with scan rate. Carbon-fiber microelectrodes can be made more sensitive to dopamine by electrochemical pretreatments or extended scan potentials that change its surface chemistry (36,37 ). The tradeoff for increased sensitivity with electrochemical treatment is decreased time resolution.…”

Multimembrane Carbon Fiber Electrodes for Physiological Measurements of Nitric Oxide

“…Carbon fibers (35-40 mm diameter; Avco, Lowell Massachusetts) were sealed in glass capillaries as described previously [26]. The glass sheath at the tip was removed to expose a 200-250 mm length of carbon fiber.…”

Cyclic Voltammetric Measurements of Neurotransmitters

“…Modified electrodes distort the temporal response of the sensor beyond that attributable to diffusion from the release site to the electrode. 9,22 This stems from the adsorptive characteristics of the electrode and, in the case of Nafion films, the time needed to diffuse through the film to the electrode surface. 20,23 Subsequent data treatment, typically deconvolution, can provide a less distorted view of the dopamine response.…”