bei Google ScholarTitelangaben
Hämmerle, Martin ; Lauterbach, Anja ; Schumacher, Matthias ; Moos, Ralf:
Electrochemical enzyme biosensor for gaseous formaldehyde.
2004
Veranstaltung: The Eighth World Congress on Biosensors
, 24.-26. Mai 2004
, Granada, Spanien.
(Veranstaltungsbeitrag: Kongress/Konferenz/Symposium/Tagung
,
Poster
)
Abstract
Formaldehyde is an ubiquitous air pollutant in indoor and outdoor atmospheres. Possible sources are disinfectants, paints, resins, particle boards, tobbaco smoke and combustion processes. It is used in large amounts in the plastics manufacturing industry. The German government has set the maximum allowed workspace concentration, MAK-value, to 0.5 ppm (v/v). For non-occupational indoor environments 0.1 ppm (v/v) are recommended. Traditional systems for the determination of formaldehyde in air consist of a sampling step (e.g. washer, adsorber) followed by a quantification step (optical, enzymatic, or titration). There are only few reports where formaldehyde is determined directly in the gas phase in one step. We present an electrochemical enzyme biosensor that can detect gaseous formaldehyde directly without a separate sampling step. NAD-dependent formaldehyde dehydrogenase converts formaldehyde to formic acid. The formed NADH is oxidised by a redox mediator (e.g. naphthoquinone). The latter is electrochemically reoxidised at an electrode (+0.2 V vs. Ag/AgCl). The measured current is related to the formaldehyde concentration in the gas phase. The aqueous phase where these redox reactions take place is separated from the gaseous sample phase by a gas permeable Teflon membrane. The sensor is characterized according to response and performance. For a gas phase concentration of 0.5 ppm (v/v) the current is about 0.9 μA. The detection limit (3 sigma) is about 0.05 ppm (v/v), the response time (t90%) at 0.5 ppm (v/v) is about 6 min. The sensor response is constant during continuous operation at 2 ppm (v/v) for at least 10 h. The life time of the sensor at room temperature and continuous operation is a few days. Additionally, a model of the processes in the sensor is presented. The sensor performance and possible design improvements are discussed according to this model.
Weitere Angaben
| Publikationsform: | Veranstaltungsbeitrag (Poster) |
|---|---|
| Begutachteter Beitrag: | Ja |
| Institutionen der Universität: | Fakultäten > Fakultät für Ingenieurwissenschaften Fakultäten > Fakultät für Ingenieurwissenschaften > Lehrstuhl Funktionsmaterialien > Lehrstuhl Funktionsmaterialien - Univ.-Prof. Dr.-Ing. Ralf Moos Fakultäten Fakultäten > Fakultät für Ingenieurwissenschaften > Lehrstuhl Funktionsmaterialien Profilfelder > Advanced Fields > Neue Materialien Forschungseinrichtungen > Forschungszentren > Bayreuther Materialzentrum - BayMAT Profilfelder Profilfelder > Advanced Fields Forschungseinrichtungen Forschungseinrichtungen > Forschungszentren |
| Titel an der UBT entstanden: | Ja |
| Themengebiete aus DDC: | 600 Technik, Medizin, angewandte Wissenschaften > 620 Ingenieurwissenschaften |
| Eingestellt am: | 29 Jun 2015 11:50 |
| Letzte Änderung: | 05 Apr 2016 06:52 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/15429 |