Abstract
The synthesis and initial evaluation of a new dye-functionalized crown-ether, 2-[2-(2,3,5,6,8,9,11,12,14,15-decahydro-1,4,7,10,13,16-benzohexaoxacyclooctadecin)ethenyl]-3-methyl benzothiazolium iodide (denoted BSD), are reported. This molecule contains a benzyl 18-crown-6 moiety as the ionophore and a benzothiazolium to spectrally transduce ion binding. Binding of K+ to BSD in methanol causes shifts in the both absorbance and fluorescence emission maxima, as well as changes in the molar absorptivity and the emission intensity. Apparent dissociation constants (Kd) in the range 30-65 mM were measured. In water and neutral buffer, Kd values were approximately 1 mM. BSD was entrapped in sol-gel films composed of methyltri-ethoxysilane (MTES) and tetraethylorthosilicate (TEOS) with retention of its spectral properties and minimal leaching. K+ binding to BSD in sol-gel films immersed in pH 7.4 buffer causes significant fluorescence quenching, with an apparent response time of approximately 2 min and an apparent Kd of 1.5 mM.
Original language | English (US) |
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Pages (from-to) | 236-242 |
Number of pages | 7 |
Journal | Luminescence |
Volume | 24 |
Issue number | 4 |
DOIs | |
State | Published - 2009 |
Externally published | Yes |
Keywords
- Crown ether
- Fluoroionophore
- Pottasium sensing
- Sol-gel
ASJC Scopus subject areas
- Biophysics
- Chemistry (miscellaneous)