Hydrophilic sensor membrane based on cation-selective protic chromoionophore.
The first potassium optode based on a protic chromoionophore immobilized in a hydrogel matrix is presented. The highly selective protic chromoionophore consists of a cryptohemispherand moiety and a trinitroanilino chromophore part. The acidifying power of potassium ions over sodium ions is 0.6 pH units. This correlates with the findings in solution. In contrast to several crown and aza-crown based chromophores the highly pre-organized moiety allows ion detection even in aqueous environment. The detection limit for potassium ions at pH 7.7 is 5 microM.
Institute of Analytical Chemistry, University of Regensburg, Chemo- and Biosensors, Germany.
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Krause
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Werner
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Huber
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Wolfbeis
D015374:Biosensing Techniques / Q000379:methods* / Q000592:standards*; D002138:Calibration; D002412:Cations / Q000032:analysis*; D002863:Chromogenic Compounds; D006863:Hydrogen-Ion Concentration; D007476:Ionophores; D009994:Osmolar Concentration; D011188:Potassium / Q000032:analysis; D012964:Sodium / Q000032:analysis; D017186:Titrimetry
D002412:Cations; D002863:Chromogenic Compounds; D007476:Ionophores; D012964:Sodium; D011188:Potassium