Characterization of potassium-selective field effect transistors based on 1,3-(di-4-oxabutanol)-calix[4]arene-crown-5 as ionophore

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. Copyright © 2009 American Scientific Publishers All rights reserved.