a physic-mathematical model has been developed that is suitable for biosensors incorporating membranes and bisubstrate enzymes. the set of equations regarding the transport of reactants across the membrane, the bisubstrate enzymatic reaction, back diffusion of reactants and reaction products, are written down and simultaneously solved and transient response of the electrode is determined as a f...

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...

Background: The RightLevelpHTM indicator is a new device designed to measure pH of gastric aspirate obtained via nasogastric tube while minimizing exposure of the operator. Study Objectives: In vivo and in vitro validation of the RightLevelpHTM indicator. Methods: Patients (23) undergoing general anesthesia had placement of a nasogastric tube and gastric pH electrode catheter following endotrac...

It lhas been possible to miniatuirize the glass pH electrode to an extent tllat it can be uised to measture the intraltiminal pH of single mammalian nephrons(l). There are, however, a nutmber of problems that arise from the miniaturization process. Thlese includ(le electrode insulation, the incorporation of a suitable reference electrode witlh the pH glass electrode, an(d the ultimate achievabl...

The electrochemical oxidation behavior of m-nitrophenol (m-NP) was studied comparatively on glassy carbon electrode, Pt electrode, PbO2 electrode, SnO2 electrode, and graphite electrode using cyclic voltammetry. The cyclic voltammetry measurements were performed in acidic (1 M H2SO4, pH 0.4), neutral (1 M Na2SO4, pH 6.8), and...

Vaginal pH measurement is a screening method of vaginal infection in pregnancy. We tested two different methods of pH determination. In freshly taken vaginal fluid measurements were carried out with special pH indicator strips and pH micro glass electrode. About 100 microliters of vaginal fluid is enough when pH indicator strips are used, and 200 microliters when the micro electrode is used. Th...

A pH-sensitive RuO₂ electrode coated in a commercial cyanoacrylate adhesive typically exhibits very low pH sensitivity, and could be paired with a RuO₂ working electrode as a differential type pH sensor. However, such sensors display poor performance in real sample matrices. A pH sensor employing a RuO₂ pH-sensitive working electrode and a SiO₂-PVB junction-modified RuO&...