Abstract: A potassium/sodium ion sensing device applying an extended-gate field effect transistor, which using an extended-gate ion sensitive field effect transistor (EGFET) as base to fabricate a potassium/sodium ion sensing device, using the extended gate of the extended-gate ion sensitive field effect transistor as a signal intercept electrode, and immobilizing the hydro-aliphatic urethane diacrylate (EB2001) intermixed with electronegative additive, potassium ionophore, sodium ionophore, and the like, to fabricate a potassium/sodium ion sensing electrode. The present invention utilizes the photocurability and good hydrophilicity of the hydro-aliphatic urethane diacrylate (EB2001), and fixes potassium/sodium ionophore, can obtain a non-wave filter, single-layer, stable signal potassium and sodium ion sensor.

Abstract: A method for fabricating an array pH sensor and a readout circuit device of such array pH sensor are implemented by utilizing an extended ion sensitive field effect transistor to construct the array pH sensor and related readout circuit. The structure of the array sensor having this extended ion sensitive field effect transistor comprises a tin dioxide/metal/silicon dioxide multi-layer structure sensor and a tin dioxide/indium tin oxide/glass multi-layer structure sensor and has excellent properties. Furthermore, the readout circuit and the sensor utilize two signal generators for controlling and reading signals. In particular, the sensor can be effective for increasing the accuracy of measurement and reducing the interference of noise.

Abstract: A process for fabricating a whole solid-state pH sensing device by using the polypyrrole as the contrast pH detector and a whole solid-state pH sensing device fabricated by the process are disclosed, wherein said device is a differential pair framework potential electrochemical sensing device fabricated by using a non-insulating solid-state inorganic ion-sensing membrane and a polypyrrole sensing membrane. The largest difference between the device of the present invention and the conventional potentiometric type pH sensor is that the sensor of the invention is a solid-state planar sensor. The differential pair framework uses tin dioxide as the ion-sensing membrane and the reference electrode, and uses a polypyrrole sensor as the differential sensor, wherein the sensitivity of tin dioxide is good and has a value up to 57 mV/pH, and the sensitivity of polypyrrole is about 27 mV/pH.

Abstract: In this invention, a potentiometric electrochemical sensor and biosensor based on an uninsulated solid-state material was presented.

Abstract: The present invention discloses a method of forming a metal layer by thermal evaporation or RF reactive sputtering in order to fabricate a light shielding layer for an ion sensitive field effect transistor. The multi-layered construction of the ion sensitive field effect transistor with a metal thin film as a light shielding layer is SnO2/metal/SiO2 or SnO2/metal/Si3N4/SiO2, and is able to lower the effect of light successfully.

Abstract: A sensitive material-tin oxide (SnO2) obtained by thermal evaporation or by r.f. reactive sputtering is used as a high-pH-sensitive material for a Multi-Structure Ion Sensitive Field Effect Transistor. The multi-structure of this Ion Sensitive Field Effect Transistor (ISFET) includes SnO2/SiO2 gate ISFET or SnO2/Si3N4/SiO2 gate ISFET respectively, and which have high performances such as a linear pH sensitivity of approximately 56˜58 mV/pH in a concentration range between pH2 and pH10. A low drift characteristics of approximately 5 mv/day, response time is less than 0.1 second, and an isothermal point of this ISFET sensor can be obtained if the device operates with an adequate drain-source current. In addition, this invention has other advantages, such as the inexpensive fabrication system, low cost, and mass production characteristics. Based on these characteristics, a disposal sensing device can be achieved. Thus, this invention has a high feasibility in Ion Sensitive Field Effect Transistor.