Nitric Oxide Microsensor for High Spatial Resolution Measurements in Biofilms and Sediments
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- 作者：Frank Schreiber ; Lubos Polerecky ; Dirk de Beer
- 刊名：Analytical Chemistry
- 出版年：2008
- 出版时间：February 15, 2008
- 年：2008
- 卷：80
- 期：4
- 页码：1152 - 1158
- 全文大小：201K
- 年卷期：v.80,no.4(February 15, 2008)
- ISSN：1520-6882
文摘
Nitric oxide (NO) is a ubiquitous biomolecule that isknown as a signaling compound in eukaryotes and prokaryotes. In addition, NO is involved in all conversions of thebiogeochemical nitrogen cycle: denitrification, nitrification, and the anaerobic oxidation of ammonium (Anammox). Until now, NO has not been measured with highspatial resolution within microbial communities, such asbiofilms, sediments, aggregates, or microbial mats,because the available sensors are not robust enough andtheir spatial resolution is insufficient. Here we describethe fabrication and application of a novel Clark-type NOmicrosensor with an internal reference electrode and aguard anode. The NO microsensor has a spatial resolutionof 60-80 
m, a sensitivity of 2 pA M-1, and a detectionlimit of ~30 nM. Hydrogen sulfide (H2S) was found to bea major interfering compound for the electrochemicaldetection of NO. The application of the novel NOmicrosensor to nitrifying biofilms and marine sedimentsrevealed dynamic NO concentration profiles with peaksin the oxic parts of the samples. The local concentrationssuggested that NO may be an important bioactive compound in natural environments. The consumption andproduction of NO occurs in separate regions of stratifiedmicrobial communities and indicates that it is linked todistinct biogeochemical cycles.
m, a sensitivity of 2 pA M-1, and a detectionlimit of ~30 nM. Hydrogen sulfide (H2S) was found to bea major interfering compound for the electrochemicaldetection of NO. The application of the novel NOmicrosensor to nitrifying biofilms and marine sedimentsrevealed dynamic NO concentration profiles with peaksin the oxic parts of the samples. The local concentrationssuggested that NO may be an important bioactive compound in natural environments. The consumption andproduction of NO occurs in separate regions of stratifiedmicrobial communities and indicates that it is linked todistinct biogeochemical cycles.