The development of an optical pH sensor based on immobilization of quinizarin (1,4-dihydroxyanthraquinone) on a triacetylcellulose membrane was described. The resulting membrane exhibited fast color change from yellow to violet, while changing the pH in alkaline region. The immobilized quinizarin showed a broader dynamic range from (pH 9.4-11.4) with respect to free form (pH 8.8-10.4). The sens...

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&...

A micro-fabricated metal-oxide based conductometric pH sensor is designed and fabricated in this manuscript. pH sensors have applications in various areas from farming to food processing, human health monitoring, industrial waste products investigation, etc. Accordingly, there is a relatively high demand for a reliable, rapid and precise pH sensor in the market. Relatively precise pH sensors ha...

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...

Front-side connected, N-channel, normally-off, chemical field effect transistor (ChemFET) microsensors including a SiO2/Si3N4 pH-sensitive gate have been fabricated using a standard P-well silicon technology. The fabrication and packaging processes are described and sensor properties and performances are demonstrated through pHmeasurements. Finally, the front-side connected ChemFETs microsensor...