NH4+-sensitive chemically modified field effect transistors based on siloxane membranes for flow-cell applications

Abstract The paper describes the design and application of electrochemical microsensors based on field effect transistors (CHEMFETs) for selective ammonium ion determination. The ammonium-sensitive sensors utilize silicon rubber polymer (Siloprene) and polysiloxane PSX 851 membranes containing nonactine as an ionophore. The performances of ammonium-sensitive CHEMFETs were determined in a flow-cell system. Designed microsensors exhibit good selectivity for ammonium ions over alkali metal cations (except potassium) and over alkaline-earth metal cations. They showed linear response in a wide range of pNH 4 + with a slope of 46–52 mV decade −1 and response times not exceeding 120 s. Best results i.e. highest values of response slope and highest selectivity over alkali metal cations were obtained for ammonium-sensitive CHEMFETs based on PSX 851 polysiloxane membranes.

[1]  Zbigniew Brzozka,et al.  Development of Durable K+-Selective Chemically Modified Field Effect Transistors with Functionalized Polysiloxane Membranes , 1994 .

[2]  Albert van den Berg,et al.  Modification of ISFESTs by covalent anchoring of poly(hydroxyethyl methacrylate) hydrogel. Introduction of a thermodynamically defined semiconductor-sensing membrane interface , 1990 .

[3]  Zbigniew Brzozka,et al.  The design of durable Na+-selective CHEMFETs based on polysiloxane membranes , 1994 .

[4]  Jiri Janata,et al.  Field effect transistors sensitive to sodium and ammonium ions , 1981 .

[5]  E. Pretsch,et al.  Lipophilicity of tetraphenylborate derivatives as anionic sites in neutral carrier-based solvent polymeric membranes and lifetime of corresponding ion-selective electrochemical and optical sensors , 1995 .

[6]  D. Reinhoudt,et al.  CHEMICALLY MODIFIED FIELD-EFFECT TRANSISTORS - POTENTIOMETRIC AG+ SELECTIVITY OF PVC MEMBRANES BASED ON MACROCYCLIC THIOETHERS , 1993 .

[7]  M. Yokoyama,et al.  Unsymmetrical calix[4]arene ionophore/silicone rubber composite membranes for high-performance sodium ion-sensitive field-effect transistors , 1992 .

[8]  Y. Umezawa,et al.  Selectivity coefficients for ion-selective electrodes: Recommended methods for reporting KA,Bpot values (Technical Report) , 1995 .

[9]  J. Bartrolí,et al.  Continuous-Flow System for On-Line Water Monitoring Using Back-Side Contact ISFET-Based Sensors. , 1996, Analytical chemistry.

[10]  D. Reinhoudt,et al.  New membrane materials for potassium-selective ion-sensitive field-effect transistors , 1990 .