Boron-Doped Diamond as a Quasi-Reference Electrode
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2022-11-21 |
| Journal | Analytical Chemistry |
| Authors | Zhen Peng, Andrea Fiorani, Kazumi Akai, Michio Murata, Atsushi Otake |
| Institutions | Keio University |
| Citations | 5 |
Abstract
Section titled āAbstractāAs a working electrode, boron-doped diamond (BDD) has been studied in detail in electrochemical processes because of its superior electrochemical properties. However, these characteristics have rarely been mentioned when BDD is used as a quasi-reference electrode (QRE). Herein, we conducted a systematic investigation on BDD electrodes, with different boron-doping levels (1 and 0.1%) and different surface terminations (hydrogen and oxygen) for their application as a QRE. A BDD electrode with 1% boron and a hydrogen-terminated surface achieved the best stability. Its open-circuit potential (OCP) exhibited less than 100 mV of potential drift over 6000 s and showed a minuscule half-wave potential difference (<i>E</i><sub>1/2</sub>) of 0.0037 V in 0.1 mM K<sub>3</sub>[Fe(CN)<sub>6</sub>]/1 M KCl solution before and after the OCP measurement. Based on these observations, anions are found to contribute to the potential, which we preliminarily speculate as related to the capacitance caused by electrostatic adsorption on the positively charged hydrogen-terminated surface. The repeatability of measurement was verified through continuous cyclic voltammetry tests in 0.1 mM K<sub>3</sub>[Fe(CN)<sub>6</sub>]/1 M KCl, showing a maximum <i>E</i><sub>1/2</sub> difference of 0.042 V. The contribution of the redox couples was excluded, and the repeatability was considered to originate from its surface stability. Finally, a linear response of the optimized BDD as a QRE was validated (<i>R</i><sup>2</sup> > 0.99) by determination of free chlorine and dopamine concentrations, respectively. These results consolidate the existing fundamental research on BDD electrodes and promote the possibility of its application as a QRE in harsh environments or <i>in vivo</i> biological monitoring.
Tech Support
Section titled āTech SupportāOriginal Source
Section titled āOriginal SourceāReferences
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