Naslov
Fluorescent potential-sensitive dyes for use in solid state sensors for potassium ion

Autori
Murković, Ivana ; Lobnik, A. ; Mohr, G.J. ; Wolfbeis, O.S.

Izvornik
Analytica Chimica Acta (0003-2670) 334 (1996), 1-2; 125-132

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
sensors; PVC membranes; polarity probes; carbocyanines

Sažetak
Fluorescent potential-sensitive dyes (PSDs) were screened for use in potassium-sensitive optical sensor membranes. A potassium-sensitive plasticized PVC layer containing valinomycin as an ion carrier, lipophilic berate salt as an anionic additive, and a PSD was chosen as a model for evaluating the applicability of PSDs. A commercial carbocyanine dye (3, 3'-dihexadecyloxacarbocyanine perchlorate) was found to exhibit the best properties in terms of signal changes, photostability and operational life-time. The sensor membrane responds reversibly to potassium ion, with fluorescence intensity changes exceeding 50% and response times being of the order of 1 min. The response to potassium is slightly pH dependent. Typically, an 8% change in intensity is observed over the range pH 5-8. The new sensor membrane exhibits significantly improved signal changes compared to previous optodes based on related sensing schemes. We also report the effects of different plasticizers and lipophilic additives on the response of the layers. The response mechanism is discussed with respect to morphology of the membrane.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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