by Keyword: Calix[4]arene
Gustavsson, J., Zine, N., Vocanson, F., Engel, E., Planell, J., Bausells, J., Samitier, J., Errachid, A., (2009). Characterization of potassium-selective field effect transistors based on 1,3-(di-4-oxabutanol)-calix[4]arene-crown-5 as ionophore 
Sensor Letters , 7, (5), 795-800
The ionophore 1,3-(di-4-oxabutanol)-calix[4]arene-crown-5 has been synthesized and used in order to develop a plasticized poly(vinyl-chloride) membrane for potassium ion detection using ion-selective field-effect transistors (ISFETs). The composition of the polymeric membrane was optimized with respect to the plasticizer being used, with the best response obtained using bis(2ethylhexyl)sebacate. The developed MEMFETs exhibit a good linear response of 52.4±1.6 mV per decade within the concentration range of 2.0 x 10-4 M to 1.0 x 10-1 M and response time of 30 seconds. The detection limit was determined to be 4 x 10-5 M and also the selectivity coefficients for possible interfering cations/anions were evaluated. The MEMFETs are suitable for use in the pH range of 3-11.
JTD Keywords: Calix[4]arene, ISFET, MEMFET, Potassium
de Oliveira, I. A. M., Risco, D., Vocanson, F., Crespo, E., Teixidor, F., Zine, N., Bausells, J., Samitier, J., Errachid, A., (2008). Sodium ion sensitive microelectrode based on a p-tert-butylcalix[4]arene ethyl ester Sensors and Actuators B: Chemical 130, (1), 295-299
Planar sodium-selective potentiometric microelectrodes with a conducting polymer (polypyrrole doped with cobaltabis(dicarbollide) ions ([3,3'-Co(1,2-C2B9-H-11)(2)](-))) as solid contact layer between the polymeric sensitive membrane and the platinum substrate have been constructed. The p-tert-butylcalix[4]arene ethyl ester was used as ionophore for sodium recognition. The microelectrode shows a linear response for Na+ concentrations between 3.0 x 10(-6) and 1.0 x 10(-1) M with a Nernstian slope of 58.65 +/- 2 mV per decade and a detection limit of 1.45 x 10(-6) M. The response time was 14 s, and the electrode is suitable for use within the pH range of 3-10.
JTD Keywords: Sodium, Polypyrrole, Calix[4]arene, Solid-state ion selective microelectrode, Potentiometric
