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.

Keywords: batch injection analysis; capillary electrophoresis; flow injection analysis; liquid chromatography; review.

Figure 1

(A) Schematic diagram of batch injection analysis (BIA) and (B) flow injection analysis (FIA) cells for BDD electrodes.

Figure 2

Flow manifold developed for FBA-DPASV and MCFA-MPA. The μP1 and μP5 were used to pump 50 μL per pulse of acetic acid/acetate solution at pH 4.0 (1) and 0.1 M H₂SO₄ (5), respectively. The μP2, μP3, μP4, and μP6 pump 20 μL per pulse of the stock solutions of Zn²⁺ (2), Pb²⁺ (3), interferents (4), and samples (6), respectively. SV1 and SV2 are the three-way valves and the waste (7), respectively. Reprinted from Bezerra dos Santos et al. (2014). Reproduced by permission of The Royal Society of Chemistry.