Localized Electrochemistry for Studying Functional Carbon Surfaces

Abstract

International audienceThe large amount of research about modified surfaces has inspired the concomitant development of analytical methods for investigating the properties of the modified interfaces. Local electrochemical methods offer new possibilities both for studying the properties of the functional interface and for following their preparation after each step. In this review, these different possibilities are illustrated with different examples of SECM analysis of modified surfaces with a special emphasis on carbon materials

Influence of Fluorene and Spirobifluorene Regioisomerism on the Structure, Organization, and Permeation Properties of Monolayers

“…Classical surface characterization techniques such as X-ray photoelectron spectroscopy (XPS) or infrared spectroscopy (IR) are not relevant techniques in these experiments as the present monolayers are mainly constituted of C and H atoms and immobilized on carbon substrates. However, fluorene and SBF derivatives are also known to be electroactive materials , and electrochemical investigations have been proven to be a powerful tool to characterize functionalized surfaces . First, ferrocyanide was chosen as a redox probe in solution to investigate the blocking behavior of the surfaces at each step of their modifications.…”

“…However, fluorene and SBF derivatives are also known to be electroactive materials 44,45 and electrochemical investigations have been proven to be a powerful tool to characterize functionalized surfaces. 46 First, ferrocyanide was chosen as a redox probe in solution to investigate the blocking behavior of the surfaces at each step of their modifications. The redox behavior of ferrocyanide has already been used to probe the formation of ethynylbenzene monolayers on carbon.…”

“…46 First, ferrocyanide was chosen as a redox probe in solution to investigate the blocking behavior of the surfaces at each step of their modifications. The redox behavior of ferrocyanide has already been used to probe the formation of ethynylbenzene monolayers on carbon.…”

SECM Investigation of Carbon Composite Thermoplastic Electrodes

“…[13][14][15][16] It has been already used to probe a variety of biological, chemical and electrochemical processes. [16][17][18][19] In feedback mode, 19,20 the active form of an electro-active species (redox mediator) is generated at the tip ultramicroelectrode (UME) where it diffuses to the substrate surface, interacts with the substrate, and then diffuses back to the UME, creating a change in the electrochemical current. Feedback mode is of interest for our study because the sample under investigation does not need to be electrically connected (in unbiased conditions), and the method permits the observation of a specific property by changing the redox mediator.…”

“…SECM is a well-known electrochemical technique complementary to cyclic voltammetry and other electrochemical methods, with the difference that SECM allows observation of electrochemical interfaces locally and from the solution side. − It has been already used to probe a variety of biological, chemical, and electrochemical processes. − In the feedback mode, , the active form of an electro-active species (redox mediator) is generated at the tip of an ultramicroelectrode (UME) where it diffuses to the substrate surface, interacts with the substrate, and then diffuses back to the UME, creating a change in the electrochemical current. The feedback mode is of interest for our study because the sample under investigation does not need to be electrically connected (in unbiased conditions), and the method permits the observation of a specific property by changing the redox mediator. ,,, Quantitative kinetic analysis can be derived from approach curves that figure the variation of the UME tip current with the tip-substrate distance, or if the tip-substrate distance is held constant, two-dimensional SECM images can be recorded.…”