Fabrication and test of sol–gel based planar oxygen optodes for use in aquatic sediments
| Autor: | Gerhard A. Holst, Michael Kühl, Bettina König, Ronnie N. Glud, Oliver Kohls |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
biology
Analytical chemistry chemistry.chemical_element General Chemistry Oceanography biology.organism_classification Fluorescence Ormosil Oxygen Perchlorate chemistry.chemical_compound chemistry Chemical engineering Hediste diversicolor Environmental Chemistry Seawater FOIL method Water Science and Technology Sol-gel |
| Zdroj: | Marine Chemistry. 97:262-276 |
| ISSN: | 0304-4203 |
| Popis: | We describe the fabrication of organically modified sol–gel (ORMOSIL) planar optodes for mapping the two-dimensional oxygen distribution in sediments. All sensor foils were based on the use of ruthenium(II)-tris-(4,7-diphenyl-1,10-phenantrolin)perchlorate, which is a fluorescent dye quenched dynamically by oxygen. Sensors made with different sol–gel immobilisation matrices, different concentrations of precursors and indicator dye, as well as different types of scattering particles coimmobilised in the sensor foil were investigated systematically. Optimal sensor performance was obtained with dye concentrations of 2–10 mmol/kg in an immobilisation matrix made of diphenyldiethoxy-silan and phenyltriethoxy-silan precursors with addition of organically coated TiO2 particles. The sensors exhibited a good mechanical stability and a high sensitivity from 0% to 100% oxygen, which remained constant over at least 36 days. The planar optodes were used with a fluorescent lifetime imaging system for direct mapping of the spatio-temporal variation in oxygen distribution within marine sediment inhabited by the polychaete Hediste diversicolor. The measurements demonstrated the spatio-temporal heterogeneity of the oxygen distribution in bioturbated sediments due to burrow structures and non-constant irrigation activity of the polychaete, which is difficult to resolve with microsensors or with traditional biogeochemical techniques. D 2005 Elsevier B.V. All rights reserved. |
| Databáze: | OpenAIRE |
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