Poly-N-vinylamid-modifizierte Elektrode als Komponente eines spektroelektrochemischen Sensors für Catecholderivate

A series of poly(N-vinyl amide) copolymers have been synthesised by radical polymerisation from N-vinylpyrrolidone (NVP) and N-vinylphthalimide (NVPH). The suitability of the copolymers for a permselective membrane for a spectroelectrochemical sensor was studied with the goal to detect catechol derivatives. A copolymer with a NVP-NVPH ratio of 3:1 exhibited the required balance of hydrophobic and hydrophilic behaviour. The copolymer was transparent to wavelengths > 300 nm. The copolymer was applied to electrodes of different materials (glassy carbon, graphite, indium tin oxide) using the spin-coating method. The copolymer adhered well to all tested materials. The resulting films were water-insoluble, flexible, colourless and thin. The film thickness was 400 – 700 nm. From the tested catechol derivatives, caffeic acid proved to be an adequate model compound for the poly(N-vinyl amide) modified spectroelectrochemical sensor. The electrochemically derived quinone of caffeic acid was detected by its pi-pi* transition at 400 nm. The hydrophobic caffeic acid was pre-concentrated in the copolymerfilm. At pH 1 the limit of detection was 25 µM for the electrochemical signal and 250 µM for the optical signal. Both detection modes exhibited a linear behaviour up to 1 mM. For the hydrophilic ferrocyanide, the copolymer film acted at pH 1 as a partial diffusion barrier and at pH 7.4 as a complete diffusion barrier. The selectivity of the copolymer was mainly based on hydrophobic interactions and the formation of hydrogen bonds rather than on electrostatic interactions.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2005

Author dc:creator

• Renner, Karin

Contributors dc:contributor

• Schäffer, Andreas

• info:eu-repo/classification/ddc/540
• Optischer Sensor
• Elektrochemischer Sensor
• Elektrode
• Modifizierung
• Polyvinylamide
• Copolymere
• Brenzcatechinderivate
• Chemische Analyse
• Chemie
• N-Vinylpyrrolidon
• N-Vinylphthalimid
• Dopamin
• Kaffeesäure
• Spektroelektrochemie
• Elektrochemie
• polymermodifizierte Elektrode
• ITO

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121642%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:59901