On-field high-resolution quantification of the cobalt fraction available for bio-uptake in natural waters using antifouling gel-integrated microelectrode arrays

Nicolas Layglon; Sébastien Creffield; Eric Bakker; Mary-Lou Tercier-Waeber

doi:10.1016/j.marpolbul.2023.114807

On-field high-resolution quantification of the cobalt fraction available for bio-uptake in natural waters using antifouling gel-integrated microelectrode arrays

Mar Pollut Bull. 2023 Apr:189:114807. doi: 10.1016/j.marpolbul.2023.114807. Epub 2023 Mar 14.

Authors

Nicolas Layglon¹, Sébastien Creffield², Eric Bakker², Mary-Lou Tercier-Waeber³

Affiliations

¹ Department of Inorganic and Analytical Chemistry, University of Geneva, Quai E.-Ansermet 30, 1211 Geneva, Switzerland. Electronic address: nicolas.layglon@unige.ch.
² Department of Inorganic and Analytical Chemistry, University of Geneva, Quai E.-Ansermet 30, 1211 Geneva, Switzerland.
³ Department of Inorganic and Analytical Chemistry, University of Geneva, Quai E.-Ansermet 30, 1211 Geneva, Switzerland. Electronic address: marie-louise.tercier@unige.ch.

PMID: 36924693
DOI: 10.1016/j.marpolbul.2023.114807

Abstract

We report the optimization, characterization, and validation of Adsorptive Square Wave Cathodic Stripping Voltammetry on antifouling gel-integrated microelectrode arrays for autonomous, direct monitoring of cobalt(II) metal species. Detection is accomplished by complexation with an added nioxime ligand. The limit of detection established for a 90 s accumulation time was 0.29 ± 0.01 nM in freshwater and 0.27 ± 0.06 nM in seawater. The microelectrode array was integrated in a submersible probe to automatically dose the complexing agent nioxime and realize an integrated sensing system. For the first time ever, the potentially bioavailable Co(II) fraction was determined in La Leyre River-Arcachon Bay continuum, enabling to evaluate the potential ecotoxicological impact of freshwater-carried Co(II) in the Arcachon Bay. The measured potentially bioavailable Co(II) concentrations were hazardous for aquatic biota along the continuum. The electrochemical Co(II) data were compared to ICP-MS data in various fractions to determine spatial Co(II) speciation.

Keywords: Adsorptive Square Wave Cathodic Stripping Voltammetry (Ad-SWCSV); Aquatic systems; Cobalt; Dynamic Co-nioxime fraction.

MeSH terms

Biofouling* / prevention & control
Cobalt*
Fresh Water
Microelectrodes
Seawater

Substances

Cobalt