Chung Yuan Christian University

National Science Council

Wen-Yaw Chung

Jung-Chuan Chou

Tai-Ping Sun

Dorota Genowefa Pijanowska

Wladyslaw Torbicz

Shen-Kan Hsiung

Chung-We Pan

Chung-Huang Yang

Yuan-Lung Chin

Stephen S K Hsiung

Chean-Yeh Cheng

Piotr Grabiec

Hung-Kwei Liao

Bohdan Jaroszewicz

Febus-Reidj Guinto Cruz

Alfred Krzyskow

Tsai-Tseng Kuo

Yeong-Tsair Lin

Lei Zhen Ce

Shao-Chun Cheng

Ying-Hsian Wang

Zhu-Ming Huang

Chiung-Cheng Chuang

Li-Te Yin

A chloride ion-selective electrode comprises: a reference electrode in contact with a reference solution; and a chloride ion-selective membrane as the interface of a sample and the reference solution, wherein the chloride-ion selective membrane comprises a chloride ion ionophore, a chloride ion-exchange resin, a plasticizer, and a polymer matrix.

Chloride ion-selective electrode

A signal readout circuit comprises a first amplifier, a second amplifier and first to fourth transistors. The signal readout circuit has a first electrode, a second electrode, and a third electrode. The signal readout circuit applied in a wide current-sensing range of amperometric chemical sensing. The readout circuit may be applied in electrochemical sensing such as glucose, so as to read out a current signal of an amperometric sensor. Through a design of low input impedance, sensing signals in a wide current range can be sensed in the readout circuit. Also, a current mirror structure is used to copy the input current to an output current, such that an output signal range of the output signals of the current circuit is not limited by a supplied voltage.

Signal readout circuit of amperometric sensor

A signal readout circuit for amperometric sensor for reading a readout signal of a sensor includes an amplifier, a first transistor, a second transistor, and a first resistor. A negative input end of the amplifier receives an input voltage, and a positive input end of the amplifier is connected to a reference electrode of the sensor. Gates of the first transistor and the second transistor are connected to an output end of the amplifier, a drain of the first transistor is connected to a counter electrode of the sensor, and a drain of the second transistor is connected to the first resistor.

Signal readout circuit for amperometric sensor

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 &#x3b2;-D-glucose oxidase and polyvinyl alcohol bearing styrylpyridinium groups are placed in 100 &#x3bc;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.

Method of fabricating electrode assembly of sensor

An electronic circuit for ion sensor with the body effect reduction includes a bridge-type floating source circuit provided with an input terminal, an output terminal reflecting the change in the potential dependent on ion concentration, and an ion-sensitive field effect transistor (ISFET) wherein one terminal of the ISFET is coupled with the output terminal; a current mirror for providing a current to the bridge-type circuit; a third transistor for receiving the operating current provided by the current mirror, identical to the current provided to the ISFET; a differential amplifying circuit, wherein one input terminal of the amplifying circuit is input with a reference voltage, and the other input terminal is coupled with the output of the bridge-type readout circuit; and a third amplifier to generate a differential output voltage compensated for the body effect, temperature and time drift effects.

Electronic circuit for ion sensor with body effect reduction

A method for fabricating a titanium nitride (TiN) sensing membrane on an extended gate field effect transistor (EGFET). The method comprises the steps of depositing a layer of aluminum on a gate terminal of the EGFET using thermal evaporation and forming the TiN sensing membrane on an exposed part of the layer of aluminum in the sensitive window as an ion sensitive sensor (pH sensor) using a radio frequency (RF) sputtering process. Because TiN is suitable for use in a standard CMOS process, all the elements in the sensing device can be mass produced and offer the benefits of low cost, high yield, and high performance.

Method for fabricating a titanium nitride sensing membrane on an EGFET

An ion sening circuit comprises a bridge sensing circuit and a differential amplifying circuit. The bridge sensing circuit detects the ion concentration of the solution in the operation mode of constant voltage and constant current. The differential amplifying circuit compares the output of the bridge sensing circuit and a floating reference voltage, thereby the delivered voltage to the bridge sensing circuit, such that the opeation mode of constant voltage and constant current is formed accordingly. The main features of the disclosed circuit are that it grounds the reference electrode and floats the source terminal. The drawbacks of not being manufactured with intergrated circuits by CMOS technology and low benefits when applied to sensor arrays are avoided by the disclosed circuit.

Electronic circuit for ion sensor

A method for fabricating a monolithic chip including multi-sensors that can detect pH, temperature, photo-intensity simultaneously and a readout circuit. As such, as well as the multi-sensors, the readout circuit also has a reduced chip area at low cost since selection switches are used to sequentially read pH, temperature and photo-intensity detecting values, wherein the readout action is completed within a clock cycle. The entire structure is fabricated with standard 0.5 &#x3bc;m CMOS IC, Double Poly Double Metal (DPDM), n-well technology and allows the integration of the on-chip signal conditioning circuitry. The chip fabricated by the method can not only sense the Ph, temperature, photo values but also apply the extended gate field effect transistor (EGFET) on the temperature and light compensation to produce realistic pH values.

Method for fabricating a monolithic chip including pH, temperature and photo-intensity multi-sensors and a readout circuit

A sensitive material-tin oxide (SnO,) 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 SnO,/SiO,gate ISFET or SnO,/Si,N,/SiO,gate ISFET respectively, and which have high performances such as a linear pH sensitivity of approximately 56&tilde;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.

Growing community of inventors

Taoyuan Hsien, Taiwan

Wen-Yaw Chung