Boron in Electroanalysis

Reviews about the broader electrochemical reactivity of boron are available and a book on contemporary boron chemistry has captured many of the early advances as well as the diversity in boron redox chemistry. Generally, the redox chemical processes can be loosely sub-divided into  

Boron Sensing, Synthesis and Supramoleeular Self-Assembly 

Edited by Meng Li, John S. Fossey, and Tony D. James 

Electroanalytical innovation and development of novel sensor electrodes are often driven by progress in materials chemistry. In particular for boron-based structures and assemblies the detection of saccharides plays a very prominent role. Monomeric as well as polymeric borate and boronic esters are reactive towards diols and lead to novel electroanalytical tools as well as new signal amplification strategies. There are many new opportunities arising and this overview will cover some of the recent developments in solid state, surface, and molecular boron structures with application in electroanalysis. 

Fig ure 8.3 A frustrated Lewis acid-Lewis base pair can bind hydrogen and react at a catalytic electrode surface similar to a boranate redox system. (Reproduced from ref. 14 with the permission of Wiley-VCH Verlag GmbH.) 

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On the other hand, different forms of doped diamond-like materials, particularly boron-doped diamond (BDD), have been widely employed as electrode materials in the form of (nanostructured) thin films [162]. The use of these materials in electroanalysis exploits the wide potential window (Fig. 6.16), chemical inertness, mechanical robustness, and small background current typical of this class of materials. 

One important electrochemical technology where diamond electrodes have made a significant impact is in the area of electroanalysis. CVD diamond offers advantages over other electrodes, especially sp carbon (e.g., glassy carbon), in terms of linear dynamic range, limit of detection, response time, response precision, and response stability. Some of the reported applications of diamond in electroanalysis are highlighted below. Unless stated otherwise, all the diamond electrodes mentioned below are boron-doped, microcrystalline thin films deposited on a conducting substrate (e.g.. Si). 

Toghill, K.E. and Compton, R.G. (2010) Metal nanoparticle modified boron doped diamond electrodes for use in electroanalysis. Electroanalysis, 22, 1947. 

The outstanding properties of diamond make it a very attractive material for use in many potential applications. In particular, the superior electrochemical properties of highly boron-doped conductive diamond films, prepared by the CVD process, have received attention from electrochemists. This article reports the fabrication of boron-doped diamond (BDD) electrodes, creating various functional structures or functional surfaces such as microdisk array (MDA) electrodes, ion-implanted BDD electrodes, and electrodes with ultrasmooth surfaces. Studies have been made of the electrochemical properties of each system and their applications in electroanalysis arediscussed. 

Wangfuengkanagul and Chailapakul [9] described the electroanalysis of ( -penicillamine at a boron-doped diamond thin film (BDD) electrode using cyclic voltammetry. The BDD electrode exhibited a well-resolved and irreversible oxidation voltammogram, and provided a linear dynamic range from 0.5 to 10 mM with a detection limit of 25 pM in voltammetric measurement. In addition, penicillamine has been studied by hydrodynamic voltammetry and flow injection analysis with amperometric detection using the BDD electrode. 

Owing to its extraordinary chemical stability, diamond is a prospective electrode material for use in theoretical and applied electrochemistry. In this work studies performed during the last decade on boron-doped diamond electrochemistry are reviewed. Depending on the doping level, diamond exhibits properties either of a superwide-gap semiconductor or a semimetal. In the first case, electrochemical, photoelectrochemical and impedance-spectroscopy studies make the determination of properties of the semiconductor diamond possible. Among them are the resistivity, the acceptor concentration, the minority carrier diffusion length, the flat-band potential, electron phototransition energies, etc. In the second case, the metal-like diamond appears to be a corrosion-stable electrode that is efficient in the electrosyntheses (e.g., in the electroreduction of hard to reduce compounds) and electroanalysis. Kinetic characteristics of many outer-sphere... 

Boron-doped diamond is electrically conducting and has found applications as electrode material in waste-water treatment, ozone generation, electroanalysis, and trace metal detection [ii]. Due to their exceptional chemical inertness and mechanical strength, diamond electrodes have been proposed for applications in extremely aggressive media such as strong acids or plasmas. See also -> carbon electrodes. 

The latest developments in boronic acid chemistry for applications to electroanalysis are discussed by Marken. Boron and its derivatives used as Lewis acidic units have many applications for a range of nucleophilic targets in... 

Yardim, Y. (2011) Sensitive detection of capsaicin by adsorptive stripping voltammetry at a boron-doped diamond electrode in the presence of sodium dodecylsulfate. Electroanalysis, 23, 2491-2497. 

Maixnerova, L., Barek, J. and Peckova, K. (2012) Thin-layer and wall-jet arrangement of amperometric detector with boron-doped diamond electrode comparison of amperometric determination of aminobiphenyls in HPLC-ED. Electroanalysis, 24, 649-658. 

Ward-Jones, S Banks, C.E., Simm, A.O. etal. (2005) An in situ copper plated boron-doped diamond microelectrode array for the sensitive electrochemical detection of nitrate. Electroanalysis, 17,1806. 

Electrochemical methods of analysis (electroanalysis) have made progress by laser-assisted techniques [44, 92-94]. They were useful to detect ascorbic acid at a carbon electrode in flow injection [44]. Capabilities of pulsed laser beam illumination of gold and platinum disk electrodes were tested with the well-known redox couples toluidine blue, iodide, ferricyanide, ruthenium hexammine and ferrocene (see Fig. 4.10) [92]. Laser-activated voltammetry proved useful for selective removal of impurities from glassy carbon- and boron-doped diamond surfaces [93]. 

Welch, C.M., Simm, A.O. and Compton, R.G. (2006) Oxidation of electrodeposited copper on boron doped diamond in addic solution manipulating the size of copper nanopartides using voltammetry. Electroanalysis, 18, 965-80. 

Depending on the doping level, diamond exhibits properties either of a semiconductor (e.g., at boron content from 10 to 1000 ppm) or a poor metal (with up to 10,000 ppm of B or even higher). It is the heavily doped diamond that is used as an electrode material in electrosynthesis, electroanalysis, etc. 

Suryanarayan V, Zhang Y, Yoshihara S et al (2005) Voltammetric assay of naproxen in pharmaceutical formulations using boron-doped diamond electrode. Electroanalysis 17 925-932... 

Musilova J, Barek J, Peckova K (2011) Determination of nitrophenols in drinking and river water by differential pulse voltammetry at boron-doped diamond film electrode. Electroanalysis 23 1236-1244... 

Codognoto L, Tanimoto ST, Pedrosa VA et al (2006) Electroanalytical determination of carbaiyl in natural waters on boron doped diamond electrode. Electroanalysis 18 253-258... 

Dejmkova H, Scampicchio M, Zima J et al (2009) Detemination of total phenols in foods by boron doped diamond electrode. Electroanalysis 21 1014-1018... 

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