Boron Doped Diamond Electrodes in Flow-Based Systems

Abstract

Boron-doped diamond (BDD) electrodes present several notable properties, such as the largest potential window of all electrode materials (especially in anodic potentials), low background and capacitive currents, reduced fouling compared to other electrodes, mechanical robustness, and good stability over time. On the other hand, flow-based systems are known as well-established approaches to minimize reagent consumption and waste generation and with good compromise between sample throughput and analytical performance (mechanization of chemical assays). This review focuses on the use of BDD electrodes for electrochemical detection in flow systems, such as flow injection analysis (FIA), batch injection analysis (BIA), high performance liquid chromatography (HPLC), and capillary electrophoresis (CE). The discussion deals with the historical evolution of BDD, types of electrochemical pre-treatments (cathodically/H-terminated or anodically/O-terminated), cell configurations, and analytical performance. Articles are discussed in chronological order and subdivided according to the type of flow system: FIA, BIA, HPLC, and CE.

Analytical Applications of Electrochemically Pretreated Boron‐Doped Diamond Electrodes

“…In the early 1990’s, researchers began to investigate the electrochemical properties of a new form of carbon: boron‐doped diamond (BDD) . The advent of sp 3 carbons, including single crystal diamond and microcrystalline, nanocrystalline and ultrananocrystalline diamond thin films produced by chemical vapor deposition (CVD), has given researchers the opportunity to explore a wide range of electrochemical applications . For microcrystalline BDD thin films, these applications are related to interesting properties such as: (i) very wide potential window, (ii) low background currents, (iii) weak molecular adsorption (reduced fouling), (iv) rapid charge‐transfer kinetics for many redox systems, (v) microstructural stability under harsh conditions, (vi) high oxidation power, and (vii) optical transparency.…”

“…For microcrystalline BDD thin films, these applications are related to interesting properties such as: (i) very wide potential window, (ii) low background currents, (iii) weak molecular adsorption (reduced fouling), (iv) rapid charge‐transfer kinetics for many redox systems, (v) microstructural stability under harsh conditions, (vi) high oxidation power, and (vii) optical transparency. The first four of these properties make BDD a very attractive and versatile electrode material for analytical applications . In many cases its versatility is extended by different functionalizations, including nanoparticles, biomolecules, and organic chromophores .…”

Comparison of Carbon‐based Electrodes for Detection of Cresols in Voltammetry and HPLC with Electrochemical Detection

“…Unmodified BDD electrodes were also used as an anode for electrochemical incineration of cresols [3,5,[40][41][42]. The unique properties of this electrode material, such as good mechanical and chemical stability, low background current, wide potential window in the anodic region, and high resistivity to adsorption of organic compounds have been utilized in a number of voltammetric methods for determination of various oxidizable compounds [43][44][45][46][47][48] including phenolic compounds such as phenol [49], benzophenone-3 [50], nitrophenols [51], or chlorophenols [52][53][54]. Typically, anodically pretreated BDD films were used for this purpose as they provide high stability and the possibility of electrochemical activation of the surface [55][56].…”

Electrochemical Determination of the Steroid Tibolone and Its Metabolites in Saliva Samples

“…[33][34][35] In fact, its properties are different from other commonly used carbonaceous electrodes, such as favorable electron-transfer kinetics, a wide potential range in aqueous solution (oxygen evolution at~2.0 V), low and stable background current, high corrosion resistance, good resistance to adsorption of molecules and stability in successive measurements. [33,[35][36][37][38] A single unmodified BDD electrode can be used for multiple analytical determinations for long periods of time (good robustness). Only the electrochemical pretreatment needs to be constantly repeated (daily or weekly, depending of the degree of the deactivation or contamination of the electrode surface during the analysis).…”