The potassium-selective glass membranes like KAS,,_, and NAS,,_, are approx. IO times more sensitive to K+ than to Na +lp3. Since the concentration ratio of Na+/K+ in blood serum is around 35-40 and since there is at best a K+ over Naf selectivity in glass electrodes of IO, a separate measurement of the Na+ concentration is needed to correct the reading of the K+ sensor 4. Because of the depend...

A hydrogen ion-selective poly(vinyl chloride) membrane electrode was constructed using 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetracyanomethoxycalix[4]arene as a neutral carrier. The electrode showed an apparent Nernstian response in the 2-11.5 pH range with a slope of 54.0 +/- 0.2 mV/pH at 20 +/- degrees C. This electrode showed a rapid response of the emf to changes in the pH, high ion selec...

Thin-film electrodes for a low-power direct methanol fuel cell DMFC were prepared by incorporating carbon-supported Pt nanoparticles Pt/C into a silicon dioxide glass matrix. The SiO2 matrix was prepared via a sol-gel technique where tetraethyl orthosilicate TEOS was hydrolyzed by H2O in the presence of methanol. The Pt/C was stirred into the sol and the resulting mixture was applied to a glass...

• Caldwell* was the first to measure directly the pH of large cells (crab muscle fibres) with a glass electrode. Kostyuk and Sorokina reduced considerably the dimensions of the glass electrode and measured directly the intracellular pH of sartorius muscle (frog). Finally, Carter first measured the intracellular pH of a mammalian cell (rat voluntary muscle) by means of a double-barreled microele...

Three pH electrodes in clinical use were examined--(1) antimony electrode with remote reference electrode (Synectics 0011), (2) glass electrode with remote reference electrode (Microelectrodes Inc. MI 506) and (3) combined glass electrode with integral reference electrode (Radiometer GK2801C). In vitro studies showed that both glass electrodes were similar and superior to the antimony electrode...

Cell-sized lipid bilayer membrane vesicles (giant vesicles, GVs) or semi-vesicles were formed from egg yolk phosphatidylcholine on a platinum electrode under applied electric voltage by electroformation. Micromanipulation of the semi-vesicle by first pressing its membrane with a glass microneedle and then withdrawing the needle left a GV in the interior of the vesicle. During the process, an aq...

the preparation of polymer membrane selective to iron(ii) ion and its application to ion-selectiveelectrode is reported here. pvc membrane contains iron–selective n-phenylaza-15-crown-5 asionophore. the membrane electrode is highly selective to iron(ii) ion and exhibit good linearresponse over a wide concentration range of 1.0 × 10-2 to 1.0 × 10-6 m with nernstian slope of29.2 ± 0.6 mv per deca...

Methods Isolated and cleaned squid giant axons were internally perfused by a modification of the method of Adelman and Gilbert (1964) and Adelman and Fok (1964). A chemically driven syringe (Sage Instruments) was directly connected to the axon interior through a small cut in one end by means of a 200,/ diameter glass cannula. The internal axoplasm was eroded away upon continuous internal fluid ...

a highly selective electrode for bromide ion based on aza pyrilium derivative as an excellentionophore is described.the sensor exhibits a good linear response with a slope of ( 60±1 ) mv per decadeover the concentration range of ( 1×10-3 – 9×10-6 m ) , and a detection limit of ( 3×10-6 m ) of bromideions .the electrode response is independent of ph in the range of(4.0 –9.5).selectivity coeffici...

The tip potential of Ling-Gerard glass microelectrodes changes upon insertion into cells and thus impedes the determination of the actual membrane potential. The lower the membrane potential of a cell, the larger will be the error due to this tip potential. However, as is demonstrated, a relationship exists between the tip potential of the electrode and the measured potential difference, which ...