Polymer membrane electrode

An electrode in which an antibody or an antigen/hapten is incorporated in the sensing element is termed an immunoelectrode . The potential response of the immuno-electrode is based on an immunochemical reaction between the sensing element of the electrode and antibody or antigen/hapten in the sample solution. One example of such an electrode is the polymer membrane electrode shown in Fig. 7. The selective response of this electrode to specific immunoglobulins is based on the interaction between antibody in solution and an antigen-ionophore complex in the membrane ... 

T. Sokalski, A. Ceresa, T. Zwickl, and E. Pretsch, Large improvement of the lower detection limit of ion-selective polymer membrane electrodes. J. Am. Chem. Soc. 119, 11347-11348 (1997). 

J.H. Yun, V.C. Yang, and M.E. Meyerhoff, Protamine-sensitive polymer membrane electrode characterization and bioanalytical applications. Anal. Biochem. 224, 212-220 (1995). 

Redox potential pH Ionic activities Inert redox electrodes (Pt, Au, glassy carbon, etc.) pH-glass electrode pH-ISFET iridium oxide pH-sensor Electrodes of the first land and M" /M(Hg) electrodes) univalent cation-sensitive glass electrode (alkali metal ions, NHJ) solid membrane ion-selective electrodes (F, halide ions, heavy metal ions) polymer membrane electrodes (F, CN", alkali metal ions, alkaline earth metal ions)... 

By running a potentiometric precipitation titration, we can determine both the compositions of the precipitate and its solubility product. Various cation- and anion-selective electrodes as well as metal (or metal amalgam) electrodes work as indicator electrodes. For example, Coetzee and Martin [23] determined the solubility products of metal fluorides in AN, using a fluoride ion-selective LaF3 single-crystal membrane electrode. Nakamura et al. [2] also determined the solubility product of sodium fluoride in AN and PC, using a fluoride ion-sensitive polymer membrane electrode, which was prepared by chemically bonding the phthalocyanin cobalt complex to polyacrylamide (PAA). The polymer membrane electrode was durable and responded in Nernstian ways to F and CN in solvents like AN and PC. 

Figure 15-21 Response of Pb21 liquid-based ion-selective electrode with (black curve ) conventional filling solution containing 0.5 mM Pb2 or (colored curve) metal ion buffer filling solution in which [Pb2 ] =10 12 M. [From T. Sokalski, A. Ceresa. 1 Zw ickl, and E. Pretsch, "Large Improvement of the Lower Detection Limit of Ion-Selective Polymer Membrane Electrodes," J. Am. Chem. Soc. 1997, 119, 11347J...

One useful aspect of the ISE approach is the ease with which selectivity testing can be performed. Once the polymer is employed as the active ingredient in a polymer membrane electrode, the binding can be examined by measuring the potential of a cell as outlined below. We have seen that the selectivity obtained by batch extraction procedures gives the same affinity series as that measured by using the polymer in an electrode [11]. 

Glass membrane and polymer membrane electrodes are two types of ISEs that are commonly used in chnical chemistry applications. 

Steinle, E. D. Amemiya, S. Btihlmann, P. Meyerhoff, M. E., Origin of non-nernstian anion response slopes of metalloporphyrin-based liquid/polymer membrane electrodes, Anal. Chem. 2000, 72,5766-5773... 

As far as detection limits, selectivity, and Nemstian response ranges, the performance of CWEs is essentially analogous to that of conventional polymer membrane electrodes. However, one major drawback to their use appears to be the lack of reproducible potentials. Even within a single day, cell potentials can vary substantially for the same standard solution. As a result, CWEs must be recalibrated often, or better yet, standard addition or titration techniques must be utilized to ensure accurate results. Obviously, such analytical techniques could not be employed if in situ determinations are desired. 

While the majority of enzyme electrodes fabricated have been rather large devices, there have been some recent reports concerning the development of miniaturized and even microsensors. For example, MeyerhoflF (M5) prepared an essentially disposable urea sensor (tip diameter 3 mm) by immobilizing urease at the surface of a new type of polymer-membrane electrode-based ammonia sensor (see Fig. 4). Alexander and Joseph (Al) have also prepared a new miniature urea sensor by immobilizing urease at the surface of pH-sensitive antimony wire. Similarly, lannello and Ycynych (II) immobilized urease on a pH-sensitive iridium dioxide electrode. In these latter investigations, ammonia liberated from the enzyme-catalyzed reaction alters the pH in the thin film of enzyme adjacent to the pH-sensitive wire. 

B4. Baum, G., Lyim, M., and Ward, F. B., Polymer membrane electrodes. Part 1. A choline ester-selective electrode. Anal. Chim. Acta 65, 385-391 (1973). 

Greenburg, J. A., and Meyerhoff, M. E., Response properties, applications and limitations of carbonate-selective polymer membrane electrodes. Anal. Chim. Acta 141,57-64 (1982). 

M5. Meyerhoff, M. E., Preparation and response properties of selective bioelectrodes utilizing polymer membrane electrode-based ammonia gas sensors. Anal. Lett. 13,1345-1357 (1980). 

M. E. Meyerhoff and Y. M. Fraticelli, Flow Injection Determination of Ammonia-N Using Polymer Membrane Electrode-Based Gas Sensing System. Anal. Lett., 14 (1981) 415. 

In practice, the selectivity of polymer membrane electrodes can be evaluated using the well known Nicolsky equation ... 

Such a differential gas sensing system is composed of two working gas sensors, each with a different inner ion-selective polymer membrane electrode as the transducer. For example, a differential ammonia sensing arrangement involves the use of two ammonia sensing probes whose... 

Ammonium ion-selective electrodes with permeable membrane and gas-sensing polymer membrane electrodes (see subsection 2.1.5) have been applied for the determination of ammonia [344] and are applicable to any species yielding ammonia. The extensive use of membrane electrodes selective to nitrogen-containing compounds on the basis of corresponding ammonium salts incorporated into a PVC matrix was reviewed by Hansen et al. [345]. 

Glazier, S.A. and Arnold, M.A., Phosphate-selective polymer membrane electrode. Analytical... 

Sun, C.J., Sun, X.X. and Aboul-Enein, H.Y. (2010) Polymer membrane electrode based on a zinc(II) Schiff base complex for the selective determination of sodium benzoate. Anal. Lett., 43, 1989-1998. 

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