Abstract: The present invention discloses a plastic potentiometric ion-selective sensor based on field-effect transistors which can be fabricated to form the miniaturized component via sputtering and/or printing method. A plastic potentiometric ion-selective sensor doesn't need an additional bias voltage to convert the signals. The disclosed plastic sensor comprises a plastic substrate, at least one working electrode formed on the plastic substrate, a reference electrode printed on the substrate, and a golden finger printed on the plastic substrate. The golden finger is for electrically coupling with the external world and for outward transmission of signals detected at the working electrode and the reference electrode. The disclosed plastic potentiometric ion-selective sensor is replaceable.

Abstract: An optical gas concentration sensor and method for measuring blood gas based on the light adsorption sensing technique are disclosed. The optical gas concentration sensor comprises a light source, a photo detector, and a gas filtering membrane for separating the indicator and a liquid. A gas in the liquid diffuses to the indicator through the gas filtering membrane so as to change the color of the indicator due to the chemical reaction occurred between the indicator and the gas. Then, the photo detector receives the light passing though the reacted indicator from the light source. The gas concentration is determined based on pH-sensitive absorbance spectrum of the indicator.

Abstract: An amperometric sensor for uric acid and a manufacturing method thereof are disclosed, in which polyacrylamide is used to fix catalase, uricase and ferrocenecarboxylic acid on a working electrode. In determining concentration of uric acid, hydrogen peroxide is produced when enzyme and uric acid react with each other and then a reduction current generated from enzyme on the electrode with an external voltage 200 mV applied is detected. In determining concentration of uric acid, a concentration range of 2.5-20 mg/dl is achieved and sensibility of the sensor in a linear portion is 5.17 uAcm?2(mg/dl)?1. In addition, reaction time required for the reaction between enzyme and uric acid is 5.17 uAcm?2(mg/dl)?1.

Abstract: In this invention, a separative structure of the ion-selecting electrode is applied to fabricate the dual type potentiometric biosensor for creatinine detection. According to the fabrication process, the creatinine enzyme is immobilized onto a conductive layer of a substrate of pH sensing membrane and ammonium ion-selecting membrane. The conductive layer provides with a sensing region and a non-sensing region. A conductive line is extended from the conductive layer for using as an external electrical contact point. The dual type potentiometric creatinine biosensor was fabricated by using the enzyme immobilization method onto the surface of the selecting membrane of sensing membrane of pH sensing electrode and creatinine sensor.

Abstract: An ion solution concentration-detecting device includes a working electrode, a reference electrode, and a link element. The working electrode and the reference electrode are inserted into the link element. The working electrode, inserted into the link element, is replaceable, for the better sensitivity to the different ion solution. The working electrode being a contact-detecting electrode can be replaced by another contact-detecting electrode with different sensing membrane. The reference electrode includes a polymeric membrane with ion material covering silver/silver chloride (Ag/AgCl) electrode to provide a fixed and stable electrical potential. The working electrode may be a contact-detecting electrode having a sensing membrane. The sensing membrane may be a metal oxide or a polymer with ion material for measuring different ion solution effectively.

Abstract: This invention provides an extended gate ion-sensitive field effect transistor as a pH sensor for measuring the pH value of a solution under test. This invention also provides a pH sensing system comprising a separable and flexible pH sensor for measuring the pH value of a solution under test, wherein the transistor of the pH sensor can be prevented from direct contact with the solution.

Abstract: A wireless pH measurement system is disclosed, the wireless pH measurement system includes a portable module and a receiver end. The portable module comprises a signal detecting and processing portion and a wireless transmission portion. The signal detecting and processing portion comprises a sensor unit for detecting a pH signal, amplifying, filtering noise, analog/digital conversion and numerical processing to generate a pH measurement signal. The wireless transmission portion receives the pH measurement signal via a transmission interface and transmits by a Bluetooth module. The receiver end includes a Bluetooth receiver for receiving the pH measurement signal. The receiver end processes the pH measurement signal by programs, displays, analyzes and stores the pH measurement signal and transmits warning signal when an abnormal pH measurement signal is received.

Abstract: A data acquisition system for a solid-state urea biosensor uses an amplifier, a low-pass filter and a data acquisition card to acquire and relay data to a computer to be analyzed by a signal analysis program and displayed on a display panel. The biosensor includes a substrate, and three individual sensing areas separated by an insulating layer on the substrate. Each individual sensing area contains a conductive layer on the substrate, and a pH sensitive membrane is deposited thereon. An enzyme layer is deposited on one of the pH sensitive membranes to form a working electrode. The other two sensing areas are a quasi-reference electrode and a contrast electrode, respectively. The signals are transferred to an instrumentation amplifier. The amplified signals are then transferred to a low-pass filter. The filtered signals are analyzed by the program and then displayed on the display panel.

Abstract: The present invention discloses a potentiometric biosensor for urea and creatinine detection, and the forming method thereof. The disclosed biosensor comprises a substrate, at least two working electrode on the substrate, at least one reference electrode on the substrate, an internal reference electrode on the substrate, and a packaging structure which separates the adjacent electrodes. The working electrode comprises urease or creatinine iminohydrolase (CIH). The detection signal is transmitted for further processing through a wire or an exposed surface on the biosensor. The disclosed biosensor is replaceable.

Abstract: A method of fabricating an electrode assembly of a sensor is described. The sensor has a field effect transistor. The electrode assembly is separated from the field effect transistor by only a conductive line. The sensor is functioned to detect different glucose concentrations. A solid layer of tin oxide is deposited on a substrate board. A ?-D-glucose oxidase and polyvinyl alcohol bearing styrylpyridinium groups are placed in 100 ?l of sulfuric acid, to form an enzyme mixture. The enzyme mixture is dropped on the solid layer of tin oxide. The enzyme mixture is dried. The enzyme mixture is exposed to a UV ray. The enzyme mixture is dried and stabilized. The enzyme mixture is immersed in a sulfuric buffer.

Abstract: A reference electrode is disclosed. The reference electrode is developed by spreading an aqueous KCl gelling agar solid gel/poly(vinyl chloride)carboxylated (PVC—COOH) double layer on a screen-printing Ag/AgCl electrode body. Such polymer double layer can maintain ion concentration and keep stable chemical capacitance potential during measurement. The reference electrode of the present invention provides fast response time and high stability for major ions detection measurements in a wide range.

Abstract: A sensor for sensing and measuring a concentration of urea in a sample has an ammonium ion selective membrane and urease enzymes immobilized on the ammonium ion selective membrane. The urease enzymes enzymatically convert urea into ammonium ions, which is sensed by said ammonium ion selective membrane and transformed into a signal. A detector system is used for processing signal from said ammonium ion selective membrane to generate a response potential that corresponds to the concentration of urea in the sample.

Abstract: The present invention discloses a potentiometric biosensor for detecting lactate in food, and the forming method thereof. The disclosed biosensor comprises a substrate, and conducting layer on the substrate, an oxide layer on the conducting layer, and an enzyme layer on the oxide layer, wherein the enzyme layer comprises Lactate dehydrogenase (LDH). The detection signal is transmitted for further processing through a wire connected to the conducting layer, or a window formed on the surface of conducting layer.

Abstract: The present invention discloses a potentiometric biosensor for detecting creatinine, and the forming method thereof. The disclosed biosensor comprises a substrate, a working electrode formed on the substrate, a first reference electrode formed on the substrate, a second reference electrode formed on the substrate, and a packaging structure which separates the above-mentioned three electrodes. The working electrode comprises creatinine iminohydrolase (CIH). The detection signal is transmitted out from the biosensor for further processing through a wire or an exposed surface. The disclosed biosensor is replaceable.

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 differential pair framework uses tin dioxide as the ion-sensing membrane and the reference electrode, and uses a polypyrrole sensor as the differential sensor so that the sensing device framework has practicability. Since the sensitivity of the polypyrrole can be controlled by means of its polymerization, a sensing device with controllable sensitivity can be fabricated for applying to the fabrication of a pH sensor or a biosensor.

Abstract: A portable multi-ions sensing system is provided.

Abstract: The present invention discloses a reference electrode. According to the invention, a capillary structure is plugged in a solid state electrolyte layer of the reference electrode. By capillary phenomenon, a test solution is sucked to the solid state electrolyte layer to have reaction. Therefore, according to the invention, a test solution can be measured by simply placing the capillary structure of the reference electrode into the test solution. The lifetime of the reference electrode can be greatly extended.

Abstract: The present invention discloses an optical sensor for measuring blood gas, used to measure gas concentration in a liquid, comprising: an indicator solution; a first conduit for filling with the indicator solution wherein the first conduit passes through the liquid and the gas in the liquid can diffuse into the first conduit to react with the indicator solution so as to change the color of the indicator solution; a second conduit for receiving the reacted indicator solution in the first conduit; and a light emitter and a photodetector provided in opposition to each other at the two sides of the second conduit wherein the light emitter emits light towards the second conduit and the photodetector receives the light passing through the second conduit and the reacted indicator solution and thereby outputs a sensing signal depending on the received light intensity.

Abstract: This invention discloses a voltage-type gas concentration sensor and sensing method thereof. An ionic sensing electrode, a solid electrolyte membrane and a gas-permeable membrane are provided. The ionic sensing electrode comprises a sensing window. The solid electrolyte membrane is disposed on the sensing window. The gas-permeable membrane is disposed on the solid electrolyte membrane. By detecting the change of a reaction voltage as a result of reaction between the ionic sensing electrode and a solution to be measured, the invention is able to determine the pH of the solution to be measured.

Abstract: A multi-ion potential sensor is disclosed. The multi-ion potential sensor comprises a substrate, a conductive layer, an isolation layer, a tin oxide (SnO2) layer and a selective layer. The conductive layer comprises a plurality of independent conductive areas, wherein every conductive area comprises a readout area, a transmissive area and a sensing area, and the transmissive area of every conductive area is packaged by the isolation layer. The tin oxide layer comprises a plurality of independent tin oxide areas, wherein every tin oxide area is deposited on the sensing area, and the selective layer comprises a plurality of independent selective areas, wherein every selective area is set on the tin oxide area. The multi-ion potential sensor has various advantages, such as good sensitivity, low cost, simplicity, disposable, portable and data acquisition by a computer for different applications.