•The importance of tris(2,2′-bipyridine)ruthenium (II) Ru(bpy)32+ for Electrogenerated Chemiluminescence (ECL) applications is acknowledged.•Photophysics and electrochemistry of Ru(bpy)32+ are ...reported.•The ECL properties and electrochemistry of several ruthenium complexes obtained by ligand design reported from 2008 onward are reviewed.
Electrogenerated chemiluminescence, or electrochemiluminescence (ECL), is nowadays a powerful transduction method in electroanalysis, in particular regarding the application in clinical diagnostics. Indeed, its superior capability relies in the fruitful combination of electrochemical and photoluminescence properties. The research on efficient ECL luminophores has brought a wide range of molecules, form organic systems to inorganic complexes, however, despite this large pool of luminophores available, tris(2,2′-bipyridine)ruthenium (II) Ru(bpy)32+ is still leading since the first report in 1972, in both academic research and commercially available systems. To acknowledge the outmost importance of this inorganic complex, here we report the photophysical and electrochemical properties of Ru(bpy)32+ and its derivatives obtained by ligand design for application in ECL.
The oxidation of dopamine (DA) on a boron-doped diamond (BDD) electrode was investigated using in situ attenuated total reflection infrared spectroscopy (ATR-IR) and infrared reflection absorption ...spectroscopy (IRAS). Voltammogram showed multiple anodic/cathodic peaks for the oxidation/reduction of DA and its oxidized derivatives on the BDD electrode. The oxidation/reduction species on the surface and in solution were assigned using ATR-IR and IRAS, respectively. The anodic oxidation of DA promoted polymerization, and the polymerized DA (PDA) was continuously deposited on BDD without being reduced by potential cycles, which resulted in the irreversible behavior of the voltammogram. A decrease in the oxidation current of DA by potential cycles was due to the deposition of PDA. Some intermediate quinone species, such as dopaminequinone and dopaminechrome, were reversibly reduced to hydroquinone.
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Boron-doped diamond electrodes have attracted increasing interest from researchers due to their outstanding properties for electroanalysis and other electrochemical applications. Material quality and ...availability have come a long way since the initial reports on the basic electrochemical properties back in the late 1980s and early 1990s. In this review, we highlight how diamond electrochemistry has diversified and matured in recent years in terms of the understanding of structure-property relationships and the development of new applications of materials in electroanalytical chemistry.
The long-term durability of boron-doped diamond electrodes (BDD) used continuously in the electrochemical conversion of CO2 to formic acid was investigated. Although the Faradaic efficiency (FE) for ...the production of formic acid decreased with increasing electrolysis time, the FE was easily recovered by electrochemical oxidation of the BDD electrodes in H2SO4, Na2SO4 or K2SO4 solutions. For practical application, the long-term production of formic acid using BDD electrodes can be successfully accomplished just by successive polarity reversal of plus and minus terminals. Furthermore, at a current density of −20 mA cm–2, the rate of production reached 328 μmol h–1 cm–2, which is the highest value ever obtained using plate electrodes. Consequently, we found that BDD electrodes are ideal for industrial application of CO2 reduction.
Nanodiamonds (NDs) are a type of biocompatible nanomaterial with easily modified surfaces and are considered as promising candidates in biomedicine. In this work, the inhibition of tumor cell ...migration by carboxylated nanodiamonds (cNDs) was investigated. AFM-based single cell adhesion and F-actin staining experiments demonstrated that cNDs treatment could enhance cell adhesion and impair assembly of the cytoskeleton. The mechanism analysis of the regulatory protein expression level also proved that cNDs could inhibit the migration of Hela cells by preventing the epithelial–mesenchymal transition (EMT) process through the transforming growth factor β (TGF-β) signaling pathway. The in vivo pulmonary metastasis model also showed that cNDs effectively reduced the metastasis of murine B16 melanoma cells. In summary, cNDs have been demonstrated to inhibit cancer cell migration in vitro and decrease tumor metastasis in vivo. Therefore, cNDs might have potential utility for specific cancer treatment.
The electrochemical reduction behavior of hypochlorite ions (ClO−) and hypochlorous acid (HClO) at the surface of boron-doped diamond electrodes is presented. The ClO− reduction behavior is strongly ...affected by the dissolved oxygen through homogeneous oxygen recovery reaction between ClO− and H2O2 as ORR product. As for HClO reduction, one-electron mechanism which is a peculiar characteristic of boron-doped diamond electrodes, was observed.
•Observation of the first reduction stage of HClO at a BDD electrode•The observation of a one-electron reduction is peculiar to BDD.•Characteristic as nonactive electrode allows to observe of one-electron reduction.•ClO− is considered as product of one-electron reduction of two HClO.•ClO− reduction proceeds through ORR by chemical reaction with H2O2.
Preparation of stable iridium-modified boron-doped diamond electrodes through electrodeposition was studied. The electrode was prepared by wet chemical seeding and thermal annealing that performed ...before and after the electrodeposition process in order to get a homogeneous deposition. The modified electrode from each step was characterized using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), Raman and X-Ray photoelectron spectroscopy (XPS) to understand the surface topography and its elemental composition. In addition, cyclic voltammetry for arsenic (III) was performed to examine the electrochemical behavior of the modified diamond. At an optimum condition in a phosphate buffer solution pH 3 and a scan rate of 50 mV/s, a linear calibration curve in the concentration range of 1–100 μM with a detection limit of 4.64 μM was achieved. Excellent stability and repeatability were also observed with relative standard deviations of 2.6% and <0.4%, respectively. Additionally, the electrode exhibited good linearity and sensitivity towards the measurement of arsenic (III) in both arsenic (III)-added tap water and lake water samples.
Illustration of the preparation of iridium-modified BDD electrode for electrochemical detection of arsenic (III). Display omitted
•Stable iridium-modified boron-doped diamond was prepared.•Three deposition steps, including wet chemical seeding, electrodeposition, and thermal annealing were performed.•For each step, the change of material was studied.•Good performance was shown by the modified BDD for an application in arsenic sensors.
The electrochemical reduction of carbon dioxide in aqueous solutions using boron-doped diamond (BDD) electrodes was investigated at ambient pressure and temperature. We discuss the effects of the ...alkali-metal (AM) cations, K
+
, Na
+
, Rb
+
and Cs
+
, on the faradaic efficiency (FE) for the formation of formic acid. An FE of 71% was achieved in the case of a 0.075 M Rb
+
solution neutralized to pH 6.2 by the addition of HCl. In the case of a Cs
+
solution neutralized to pH 6.2, the highest FE was obtained with the more dilute concentration of 0.02 M. Of the four different solutions examined, the lowest FE was observed for the Na
+
solution. Moreover, we found that the productivity for the production of formic acid is higher at higher current densities.
Rb
+
cations provide a greater effect on the electrochemical conversion of CO
2
to formic acid using BDD electrodes.
Controlled surface functionalization of electrode materials is an important technique in various fields such as analytical chemistry, molecular electronics, and molecular recognition in biological ...systems. In this work, we report the control decoration of boron-doped diamond (BDD) electrodes by electrochemically driven copper(I)-catalyzed Huisgen 1,3-dipolar cycloaddition of alkyne and azide (e−CLICK) in which the catalyst is produced by electroreduction of copper(II) species. As the e−CLICK strategy enabled to tune the produced amount of the copper(I) catalyst electrochemically, the alkyne-terminated BDD electrodes were decorated with azide-terminated ferrocene in a controlled manner.
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