Scanning electrochemical microscopy analysis

Sridhar A, de Boer HL, van den Berg A, Le Gac S (2014) Microstamped petri dishes for scanning electrochemical microscopy analysis of arrays of microtissues. PLoS One 9(4) e9361, 1-7... 

Kinetic analysis of titanium nitride thin films by scanning electrochemical microscopy... 

Analysis of the activity of f-galactosidase from E. Coli by scanning electrochemical microscopy (SECM)... 

Bath, D.B., et al. 2000. Scanning electrochemical microscopy of iontophoretic transport in hairless mouse skin. Analysis of the relative contribution of diffusion, migration, and electroosmosis to transport in hair follicles. J Pharm Sci 89 1537. 

Basame, S.B., and H.S. White. 1999. Scanning electrochemical microscopy of metal/metal oxide electrodes. Analysis of spatially localized electron-transfer reactions during oxide growth. Anal. Chem. 71 3166-3170. 

Scanning electrochemical microscopy (SECM the same abbreviation is also used for the device, i.e., the microscope) is often compared (and sometimes confused) with scanning tunneling microscopy (STM), which was pioneered by Binning and Rohrer in the early 1980s [1]. While both techniques make use of a mobile conductive microprobe, their principles and capabilities are totally different. The most widely used SECM probes are micrometer-sized ampero-metric ultramicroelectrodes (UMEs), which were introduced by Wightman and co-workers 1980 [2]. They are suitable for quantitative electrochemical experiments, and the well-developed theory is available for data analysis. Several groups employed small and mobile electrochemical probes to make measurements within the diffusion layer [3], to examine and modify electrode surfaces [4, 5], However, the SECM technique, as we know it, only became possible after the introduction of the feedback concept [6, 7],... 

Refs. [i] Bard AJ, FaulknerLR (2001) Electrochemical methods, 2nd edn. Wiley, New York, chaps. 5, 6, 9, 11, 12 [ii] Bard AJ, Mirkin MV (eds) (2001) Scanning electrochemical microscopy. Marcel Dekker, New York [Hi] Oldham KB, Myland JC (1994) Fundamentals of electrochemistry. Academic Press, New York, chap. 8 [iv] Zoski CG (1996) Steady-state voltammetry at microelectrodes. In Vanysek P (ed) Modern techniques in electro analysis. Wiley, New York... 

Thin layer concepts may also be involved in metal deposition into thin films of mercury during stripping analysis, in (electro)chemical processes in adsorbates, films or precipitates on modified electrodes, or in scanning electrochemical microscopy. 

E. Computer-based methods for analysis of voltammetric data Ultramicroelectrodes and Scanning Electrochemical Microscopy... 

A few years ago Bard and his group developed the technique called scanning electrochemical microscopy (SECM) which makes possible a spatial analysi,s of charge transfer processes [9]. In this method an additional tip electrode of a diameter of about 2 pm is used as well as the three other electrodes (semiconductor, counter and reference electrode). Assuming that a redox system is reduced at the semiconductor, then the reduced species can be re-oxidized at the tip electrode, the latter being polarized positively with respect to the redox potential. The corresponding tip current / [ is proportional to the local concentration of the product formed at the semiconductor surface and therefore also to the corresponding local semiconductor current, provided... 

K Borgwarth, C Ricken, DG Ebling, J Heinze. Surface-analysis by scanning electrochemical microscopy—resolution studies and applications to polymer samples. Fresenius J Anal Chem 356 288-294, 1996. 

The research of Mallouk and Smotkin [45] considered combinatorial catalyst development methods. In the combinatorial research, the tools of electrochemical analysis (steady-state and dynamic voltammetry, chronoamperometry, scanning electrochemical microscopy, spectroelec-trochemistry, complex impedance analysis) are used to test electrochemical cell. These tools allow the kinetic and mechanistic studies not readily available in nanoelectrochemistry. The research concentrated on improving the metallic catalyst, and also optimizing the interfacial contact and utilization. 

Inaba M., Siroma Z., Kawatate Y., Funabiki A., Ogumi Z. Electrochemical scanning tunneling microscopy analysis of the surface reactions on graphite basal plane in ethylene carbonate-based solvents and propylene carbonate, J. Power Sources 1997, 68, 221-226. 

The ADI method was used by Hei-nze [29] to assess the voltammetric properties at microdisc electrodes. Gavaghan [30] reported a thorough examination of optimum mesh generation and errors present in the FD analysis of the disc electrodes using the ADI method. More recently, the technique has been widely adopted in the field of scanning electrochemical microscopy [31-37] for the simulation of approach curve response and interfadal chemical reactivity. 

In this chapter, two areas are considered where the unique properties of microelectrodes have had a significant impact (i) the use of microelectrodes and arrays of microelectrodes in electroanalytical studies (in foodstuffs, in concentrated industrial solutions, analysis with minimal sample preparation), especially in combination with pulsed amperometric techniques and (ii) in scanning electrochemical microscopy (SECM note that the acronym is used for both the instrument and the technique). 

Cyclic voltammetry is probably the electrochemical technique that is simulated most often, aiming at the analysis of electrode processes with respect to mechanism, kinetics, and thermodynamics of the reaction steps as well as transport properties of the molecules involved. The simulation of processes at (ultra)microelectrodes is also popular and highly important for the analysis of scanning electrochemical microscopy experiments [10]. 

Wilhelm T, Wittstock G (2003) Analysis of interaction in patterned multienzyme layers by using scanning electrochemical microscopy. Angew Chem Int Ed 42(20) 2248-2250... 

Source Adapted from C. A. Wijayawardhana, H. B. Halsall, W. R. Heineman, in Encyclopedia of Electrochemislry (Vol. 8) (Eds. A. J. Bard, P. Stratmann), Wiley-VCH, New Yoric, submitted. ALP alkaline phosphatase C competitive assay E enzime FIA-EC flow-injection analysis with electrochemical detection GC glassy carbc He heterogeneous Ho homc eneous LC-EC liquid chromatography with electrochemical detection N non-enzyme PAPP 4-amin< henyl phosphate PP j enyl j osjdiate RDE rotating disk electrode S sandwich assay SECM scanning electrochemical microscopy. 

Five types of amperometric detection have been applied for enzyme-based ECIA. They are flow-injection analysis with electrochemical detection (FIAEC), liquid chromatography with electrochemical detection (LCEC), amperometric detection with interdigitated array electrodes (IDA), rotating disk electrode (RDE) amper-ometry, and scanning electrochemical microscopy (SECM). Of these, the two conventional types, FIAEC and LCEC, shall be discussed in this section, leaving the discussion of the other types to Section V on miniaturized immunoassays. 

Kwon, S. J. Bard, A. J. 2012. Analysis of diffusion-controlled stochastic events of iridium oxide single nanoparticle collisions by scanning electrochemical microscopy. J. Am. Chem. Soc. 134(16) 7102-7108. 

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