Interrogation of Surfaces for the Quantification of Adsorbed Species on Electrodes: Oxygen on Gold and Platinum in Neutral Media

Rodríguez‐López, Joaquín; Alpuche-Avilés, Mario A.; Bard, Allen J.

doi:10.1021/ja8050553

Cited by 144 publications

(212 citation statements)

References 48 publications

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“…Detection and quantification of Au and Pt oxides.-SI-SECM was used for the quantification of electro-generated oxides (i.e., adsorbed oxygen species) on gold and platinum electrodes at neutral pH in phosphate and TRIS buffers and with Ru(NH 3 ) 6 2+ and MV + reversible me- diator systems. 73 Good agreement was found with cyclic voltammetry at the substrate and with previous results in the literature. Evidence for the formation of "incipient oxides", not evident by conventional voltammetry, was also found.…”

Section: Surface Interrogation-secm (Si-secmsupporting

confidence: 87%

Review—Advances in Scanning Electrochemical Microscopy (SECM)

Zoski

2015

J. Electrochem. Soc.

101

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Scanning electrochemical microscopy (SECM) is unique among scanning probe methods in its quantitative rigor and in its ability to study samples in liquid environments with ease. SECM has become a popular and mature technique with a wide range of applications in electrochemical imaging, chemical kinetics, biological redox processes, and electrocatalytic reactions, among others. A major development in recent years is the ongoing shift from micrometer-scale experiments to the nanoscale. Recent advances in methodology have greatly increased the capacity of SECM to characterize interfaces at the nanoscale and to obtain molecular-level chemical information. The principles of SECM will be briefly introduced, and recent advances using this technique will be discussed. Scanning electrochemical microscopy (SECM) is a scanning probe technique and electrochemical tool that is widely used to probe surfaces and surface reactions. The instrumentation, theory, modes, and initial applications were developed in the Bard laboratories during the 1980's. SECM is now used worldwide and applications continue to be developed. A number of general reviews 1-21 and two monographs 22,23 have also been published. SECM differs from other scanning probe methods such as scanning tunneling (STM) and atomic force microscopy (AFM) in that welldeveloped electrochemical methods are used to quantitatively probe the chemistry of a substrate. SECM is based on the measurement of the current through an ultramicroelectrode (UME) tip, an electrode with a radius, a, on the order of a few nanometers to 25 μm, when it is held constant or moved in a solution in the vicinity of a substrate. Substrates range from solid surfaces, including glass, metal, polymer, and biological material, to liquids such as mercury and immiscible oil. The presence of a substrate perturbs the electrochemical response of the tip and this perturbation provides information about the nature and properties of the substrate with micrometer and nanometer resolution. SECM is also used in imaging and studying the uptake or release of chemical species from a surface, including processes in biological cells. SECM combines the virtues of electrochemistry at UMEs with the application of piezoelectric elements to position the tip in the x,y,z planes, as in STM. Steady-state SECM measurements are simpler than, but analogous to those with thin layer cells, 24-28 rotating ringdisk electrodes, 29,30 and arrays of interdigitated electrodes. 31 SECM Modes of OperationThere are several basic modes of operation of SECM that continue to be used in developing new applications. These include generation/collection and feedback modes. Most SECM measurements involve steady-state current measurements, though transient measurements are also made.Generation/collection modes.-In the generation/collection (G/C) modes of SECM, the tip is generally located at distances on the order of ten tip radii or less from the substrate and both tip, i T , and substrate, i S , currents are monitored. There are two types of SECM...

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Section: Surface Interrogation-secm (Si-secmsupporting

confidence: 87%

Review—Advances in Scanning Electrochemical Microscopy (SECM)

Zoski

2015

J. Electrochem. Soc.

101

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“…negative feedback). The aforementioned SECM feedback mode is perhaps the most widely used [15], but several other operation modes have been also proposed for localized surface characterization [12,[16][17][18]. Finally, meaningful chemical and electrochemical reactivity information can be derived quantitatively from the SECM response, as it can be described by a mathematical model that comprises the coupling between mass transport and (electro)chemical kinetic aspects [15,19,20].…”

Section: Introductionmentioning

confidence: 99%

Parylene C coated microelectrodes for scanning electrochemical microscopy

Cortés‐Salazar¹,

Deng²,

Peljo³

et al. 2013

Electrochimica Acta

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a b s t r a c tHerein, we present a simple microelectrode preparation methodology consisting in coating a platinum wire or a carbon fiber with a thin insulating Parylene C film (e.g. 1-10 m), to produce SECM probes with a small and constant probe RG (i.e. ratio between the radius of the insulating sheath and the radius of the active electrode area). After exposition of a fresh active electrode area by blade cutting, a disc shaped electrode is obtained thanks to a protective hot mounting wax layer that avoids Parylene C coating deformation and is easily removed with acetone. Stiffness and straightness of the probe can be tuned by modifying the Parylene C coating thickness and the length of the carbon fiber or platinum wire. This simple electrode preparation method is highly reproducible (c.a. > 90%). The prepared Parylene C coated microelectrodes were characterized by optical microscopy, cyclic voltammetry, scanning electrochemical microscopy (SECM) approach curves and finally applied to SECM imaging of Pt band structures in contactless and contact mode.

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“…These may be deconvoluted using a method that determines the tip-substrate distance, which can be used as a feedback mechanism for distance control during imaging of a substrate (vide infra). There are many modes of SECM, such as the feedback mode discussed [20], generation collection modes [21], redox competition mode [22], surface interrogation mode [23], direct mode [24], potentiometric mode [25], and fast-scan cyclic voltammetry (FSCV) mode [26]. The advantages and applications of these and other modes are described elsewhere and are not the focus of the present manuscript.…”

Section: Scanning Electrochemical Microscopymentioning

confidence: 99%

Advances and Perspectives in Chemical Imaging in Cellular Environments Using Electrochemical Methods

Lazenby

White

2018

Chemosensors

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This review discusses a broad range of recent advances (2013)(2014)(2015)(2016)(2017) in chemical imaging using electrochemical methods, with a particular focus on techniques that have been applied to study cellular processes, or techniques that show promise for use in this field in the future. Non-scanning techniques such as microelectrode arrays (MEAs) offer high time-resolution (<10 ms) imaging; however, at reduced spatial resolution. In contrast, scanning electrochemical probe microscopies (SEPMs) offer higher spatial resolution (as low as a few nm per pixel) imaging, with images collected typically over many minutes. Recent significant research efforts to improve the spatial resolution of SEPMs using nanoscale probes and to improve the temporal resolution using fast scanning have resulted in movie (multiple frame) imaging with frame rates as low as a few seconds per image. Many SEPM techniques lack chemical specificity or have poor selectivity (defined by the choice of applied potential for redox-active species). This can be improved using multifunctional probes, ion-selective electrodes and tip-integrated biosensors, although additional effort may be required to preserve sensor performance after miniaturization of these probes. We discuss advances to the field of electrochemical imaging, and technological developments which are anticipated to extend the range of processes that can be studied. This includes imaging cellular processes with increased sensor selectivity and at much improved spatiotemporal resolution than has been previously customary.

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Interrogation of Surfaces for the Quantification of Adsorbed Species on Electrodes: Oxygen on Gold and Platinum in Neutral Media

Cited by 144 publications

References 48 publications

Review—Advances in Scanning Electrochemical Microscopy (SECM)

Review—Advances in Scanning Electrochemical Microscopy (SECM)

Parylene C coated microelectrodes for scanning electrochemical microscopy

Advances and Perspectives in Chemical Imaging in Cellular Environments Using Electrochemical Methods

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