In this study,the multi-sensing system based on the tin oxide pH electrode for the ion-determination was presented. With the advantages of the real-time supervisory control apparatus,the measured values could be displ...In this study,the multi-sensing system based on the tin oxide pH electrode for the ion-determination was presented. With the advantages of the real-time supervisory control apparatus,the measured values could be displayed on the liquid crystal display (LCD) immediately.In this study,the basic sensor was the tin oxide pH electrode,which was fabricated by radio frequency (r.f.) sputtering system on the indium tin oxide (ITO)/glass substrate.Moreover,the major blocks of the system consist of the tin oxide electrode-based ion selective electrodes (ISEs),an analog front-ended readout circuit,a microcontroller with built-in analog to digital (A/D) converter.In addition,by the embedded system design,the measurement results can be transmitted to a portable system or computer through the Universal Serial Bus (USB) and Universal Asynchronous Receiver Transmitter (UART) interface immediately.According to the experimental results,the multi-sensing system has high performance and reliability for pH,K^+,and Na^+ detection.展开更多
An amperometric glucose biosensor based on a tin oxide (SnO_2) electrode has been developed.The SnO_2 electrode is prepared by depositing the SnO_2 thin film onto a carbon electrode.To fabricate the SnO_2 amperometric...An amperometric glucose biosensor based on a tin oxide (SnO_2) electrode has been developed.The SnO_2 electrode is prepared by depositing the SnO_2 thin film onto a carbon electrode.To fabricate the SnO_2 amperometric glucose biosensor,the glucose oxidase and electron transfer mediator (ferrocenecarboxylic acid,FcA) are coimmobilized on the SnO_2 electrode using polyacrylamide.The detection range is up to glucose concentration of 520mg/dl as the applied potential is set at 300mV. Moreover,the most merit for the SnO_2 electrode as the base electrode of the SnO_2 amperometric glucose biosensor is that it can be operated at 150mV constant applied potential.The interference reduction,detection range,sensitivity and linearity are improved as the SnO_2 thin film is deposited onto a carbon electrode.Furthermore,due to the low cost substrate and simple fabrication characteristics,a disposable amperometric glucose biosensor based on the SnO_2 electrode has been realized in this study.展开更多
An impedance type humidity sensor based on the polyacrylic emulsion containing magnesium chloride (MgCl_2) without chemical modification was investigated.The impedances of the sensor were measured from various relati...An impedance type humidity sensor based on the polyacrylic emulsion containing magnesium chloride (MgCl_2) without chemical modification was investigated.The impedances of the sensor were measured from various relative humidity in the frequency range between 0.1kHz and 100 kHz.The sensor has a good sensitivity from 60%RH to 90%RH.According to the experimental results,the response time is about 240 seconds in the adsorption process and 310 seconds in the desorption process.展开更多
Drift phenomenon has been known as the drawback of sensors and causes inaccuracy on the long-term measurement. In general,there are two methods to reduce the drift problem.One is to tune the parameters of the fabricat...Drift phenomenon has been known as the drawback of sensors and causes inaccuracy on the long-term measurement. In general,there are two methods to reduce the drift problem.One is to tune the parameters of the fabrication process to improve the properties of the front-ended device.Another is to compensate the drift phenomenon by adding extra drift compensation circuit or software in the back-ended readout circuit.In this study,a drift calibration method for the potentiometric sensor was presented and the drift calibration method was performed by using the circuit.According to experimental results,the drift phenomenon of the SnO_2 pH electrode was reduced by the drift calibration device.展开更多
Enzyme was immobilized on an ammonium ion-selective electrode by different methods.An ion-selective electrode is not completely ion-specific,and interfering ions react with the ion-selective electrode membrane,alterin...Enzyme was immobilized on an ammonium ion-selective electrode by different methods.An ion-selective electrode is not completely ion-specific,and interfering ions react with the ion-selective electrode membrane,altering the measured potential.Therefore,the characteristics of the effect of other ions on ammonium ion-selective electrode-based urea biosensors are considered.Based on the experimental results,the urea biosensor based on entrapment had a high response voltage of around 189 mV and fast response time of around 16 sec.Moreover,selectivity of the urea biosensor in different interfering ions was considered to elucidate the characteristics of ammonium ion-selective electrode-based biosensors.展开更多
Continuous intra-arterial blood gas monitoring is used clinically in hospital and intensive care unit settings.The blood gas can be detected by the colormetric indicators which are sealed in the silicone membrane.The ...Continuous intra-arterial blood gas monitoring is used clinically in hospital and intensive care unit settings.The blood gas can be detected by the colormetric indicators which are sealed in the silicone membrane.The glass tubing of the sensor should be as thin as possible since it affects response time and the bicarbonate buffer shifts the sensitivity of the sensor. In this paper,the sensitivity shifts by the bicarbonate buffer was researched.When carbon dioxide diffuses into the indicator, the carbon acid is produced and the bicarbonate buffer is used to control internal acidity.Because the sensitivity of the pCO_2 sensor is increased by controlling the concentration of the bicarbonate buffer,the bicarbonate buffer is used to obtain the optimum resolution in this investigation.Moreover,the different concentrations of the bicarbonate buffer for blood gas measurements are discussed in detail.展开更多
In this paper,the pCO_2 sensitive electrode was studied for continuous measurement.The solid electrolyte membrane and gas-permeable membrane were coated on the surface of the pH sensitive electrode which was fabricate...In this paper,the pCO_2 sensitive electrode was studied for continuous measurement.The solid electrolyte membrane and gas-permeable membrane were coated on the surface of the pH sensitive electrode which was fabricated based on the SnO_2/ITO glass substrate.According to the experimental results,the pCO_2 sensitive electrode shows the sensitivity of about 35 mV/decade in detection range between 0.1 mmol/L and 50 mmol/L.Moreover,the investigated sensing structure exhibits the convenient and pragmatic properties of the pCO_2 measurement.In summary,the advantages of the pCO_2 sensitive electrode are low-cost and disposable based on the separative structure.展开更多
In this study,tin oxide sensing membrane was derived by sol-gel method and was coated onto indium tin oxide (ITO) glass substrate by spin-coating technique to fabricate a pH sensing electrode.Besides,the morphology o...In this study,tin oxide sensing membrane was derived by sol-gel method and was coated onto indium tin oxide (ITO) glass substrate by spin-coating technique to fabricate a pH sensing electrode.Besides,the morphology of the tin oxide membrane has been discussed through the instrumental analysis.Furthermore,the sensing characteristics of the pH electrode was measured by commercial instrumental amplifier as the readout circuit.Owing to the sol-gel method has many advantages such as easy fabrication of gel solution,ability to dope other materials without any expensive fabricating equipment.Hence,it is suitable for the mass production of a disposable sensor.展开更多
This study reveals the successful design of the data acquisition system for pH sensors.The data acquisition system includes an instrumentation amplifier,a low pass filter and a calculation program.The instrumentation ...This study reveals the successful design of the data acquisition system for pH sensors.The data acquisition system includes an instrumentation amplifier,a low pass filter and a calculation program.The instrumentation amplifier used as the readout circuit has many advantages,including high input impedance,high gain,low output impedance,high CMRR and high bandwidth.The low pass filter is employed to cancel the circuit noise.The calculation program uses the two-point calibration method to calculate the sample concentration.Furthermore,this study employs Boolean function to cancel error signals.As indicated by experimental results,the readout circuit obtains the sensing signal and the calculation program calculates the pH value.Hence,this study successfully fabricates an effective data acquisition system for pH sensors.展开更多
The application of Bluetooth on the pH sensor was accomplished.Based on the experimental results,Bluetooth technology was used to measure pH values without limiting the distance.Moreover,Biuetooth technology provides ...The application of Bluetooth on the pH sensor was accomplished.Based on the experimental results,Bluetooth technology was used to measure pH values without limiting the distance.Moreover,Biuetooth technology provides low power, low cost and small volume,therefore,it can increase the practicability of the system.In this investigation,the pH value was detected by the SnO_2/ITO glass-based pH sensor.During the signal progress,the detected signal was transferred to the microchip PIC18.After that,the microchip was able to communicate with PC by the Bluetooth.Moreover,the microchip can diagnose the sensing signal and sends the warning signal by alert function.In addition,the part of PC has the ability to record the information,builds the database for analyzing the pH values,and provides a better long-distance monitoring system.展开更多
This paper presents the studying results of the sodium ion sensor device based on the SnO_2/ITO glass structure in the detection of rinsing solution for contact lenses.The selective membrane contains poly (vinyl chlor...This paper presents the studying results of the sodium ion sensor device based on the SnO_2/ITO glass structure in the detection of rinsing solution for contact lenses.The selective membrane contains poly (vinyl chloride) (PVC),bis (2-ethylhexyl) sebacate (DOS),(12-crown-4) methylmalonate (B12C4),and sodium tetrakis (4-fluoropbenyl) borate dehydrate (NaTFBD). The final weight ratios are PVC:DOS:B12C4:NaTFBD=33:66:2:2.In this condition,the sensor has performances with linear sensitivity,short response time,good repeatability and selectivity.The sensor was used to measure the rinsing solution for the contact lenses.Because the experimental results show close to the accurate value for four commercial products,this sensor can preliminary be used in detecting the rinsing solution for the contact lenses.Using this structure and sodium-sensing membrane to construct the sodium sensor is proven successfully in this application.展开更多
文摘In this study,the multi-sensing system based on the tin oxide pH electrode for the ion-determination was presented. With the advantages of the real-time supervisory control apparatus,the measured values could be displayed on the liquid crystal display (LCD) immediately.In this study,the basic sensor was the tin oxide pH electrode,which was fabricated by radio frequency (r.f.) sputtering system on the indium tin oxide (ITO)/glass substrate.Moreover,the major blocks of the system consist of the tin oxide electrode-based ion selective electrodes (ISEs),an analog front-ended readout circuit,a microcontroller with built-in analog to digital (A/D) converter.In addition,by the embedded system design,the measurement results can be transmitted to a portable system or computer through the Universal Serial Bus (USB) and Universal Asynchronous Receiver Transmitter (UART) interface immediately.According to the experimental results,the multi-sensing system has high performance and reliability for pH,K^+,and Na^+ detection.
文摘An amperometric glucose biosensor based on a tin oxide (SnO_2) electrode has been developed.The SnO_2 electrode is prepared by depositing the SnO_2 thin film onto a carbon electrode.To fabricate the SnO_2 amperometric glucose biosensor,the glucose oxidase and electron transfer mediator (ferrocenecarboxylic acid,FcA) are coimmobilized on the SnO_2 electrode using polyacrylamide.The detection range is up to glucose concentration of 520mg/dl as the applied potential is set at 300mV. Moreover,the most merit for the SnO_2 electrode as the base electrode of the SnO_2 amperometric glucose biosensor is that it can be operated at 150mV constant applied potential.The interference reduction,detection range,sensitivity and linearity are improved as the SnO_2 thin film is deposited onto a carbon electrode.Furthermore,due to the low cost substrate and simple fabrication characteristics,a disposable amperometric glucose biosensor based on the SnO_2 electrode has been realized in this study.
文摘An impedance type humidity sensor based on the polyacrylic emulsion containing magnesium chloride (MgCl_2) without chemical modification was investigated.The impedances of the sensor were measured from various relative humidity in the frequency range between 0.1kHz and 100 kHz.The sensor has a good sensitivity from 60%RH to 90%RH.According to the experimental results,the response time is about 240 seconds in the adsorption process and 310 seconds in the desorption process.
文摘Drift phenomenon has been known as the drawback of sensors and causes inaccuracy on the long-term measurement. In general,there are two methods to reduce the drift problem.One is to tune the parameters of the fabrication process to improve the properties of the front-ended device.Another is to compensate the drift phenomenon by adding extra drift compensation circuit or software in the back-ended readout circuit.In this study,a drift calibration method for the potentiometric sensor was presented and the drift calibration method was performed by using the circuit.According to experimental results,the drift phenomenon of the SnO_2 pH electrode was reduced by the drift calibration device.
文摘Enzyme was immobilized on an ammonium ion-selective electrode by different methods.An ion-selective electrode is not completely ion-specific,and interfering ions react with the ion-selective electrode membrane,altering the measured potential.Therefore,the characteristics of the effect of other ions on ammonium ion-selective electrode-based urea biosensors are considered.Based on the experimental results,the urea biosensor based on entrapment had a high response voltage of around 189 mV and fast response time of around 16 sec.Moreover,selectivity of the urea biosensor in different interfering ions was considered to elucidate the characteristics of ammonium ion-selective electrode-based biosensors.
文摘Continuous intra-arterial blood gas monitoring is used clinically in hospital and intensive care unit settings.The blood gas can be detected by the colormetric indicators which are sealed in the silicone membrane.The glass tubing of the sensor should be as thin as possible since it affects response time and the bicarbonate buffer shifts the sensitivity of the sensor. In this paper,the sensitivity shifts by the bicarbonate buffer was researched.When carbon dioxide diffuses into the indicator, the carbon acid is produced and the bicarbonate buffer is used to control internal acidity.Because the sensitivity of the pCO_2 sensor is increased by controlling the concentration of the bicarbonate buffer,the bicarbonate buffer is used to obtain the optimum resolution in this investigation.Moreover,the different concentrations of the bicarbonate buffer for blood gas measurements are discussed in detail.
文摘In this paper,the pCO_2 sensitive electrode was studied for continuous measurement.The solid electrolyte membrane and gas-permeable membrane were coated on the surface of the pH sensitive electrode which was fabricated based on the SnO_2/ITO glass substrate.According to the experimental results,the pCO_2 sensitive electrode shows the sensitivity of about 35 mV/decade in detection range between 0.1 mmol/L and 50 mmol/L.Moreover,the investigated sensing structure exhibits the convenient and pragmatic properties of the pCO_2 measurement.In summary,the advantages of the pCO_2 sensitive electrode are low-cost and disposable based on the separative structure.
文摘In this study,tin oxide sensing membrane was derived by sol-gel method and was coated onto indium tin oxide (ITO) glass substrate by spin-coating technique to fabricate a pH sensing electrode.Besides,the morphology of the tin oxide membrane has been discussed through the instrumental analysis.Furthermore,the sensing characteristics of the pH electrode was measured by commercial instrumental amplifier as the readout circuit.Owing to the sol-gel method has many advantages such as easy fabrication of gel solution,ability to dope other materials without any expensive fabricating equipment.Hence,it is suitable for the mass production of a disposable sensor.
文摘This study reveals the successful design of the data acquisition system for pH sensors.The data acquisition system includes an instrumentation amplifier,a low pass filter and a calculation program.The instrumentation amplifier used as the readout circuit has many advantages,including high input impedance,high gain,low output impedance,high CMRR and high bandwidth.The low pass filter is employed to cancel the circuit noise.The calculation program uses the two-point calibration method to calculate the sample concentration.Furthermore,this study employs Boolean function to cancel error signals.As indicated by experimental results,the readout circuit obtains the sensing signal and the calculation program calculates the pH value.Hence,this study successfully fabricates an effective data acquisition system for pH sensors.
文摘The application of Bluetooth on the pH sensor was accomplished.Based on the experimental results,Bluetooth technology was used to measure pH values without limiting the distance.Moreover,Biuetooth technology provides low power, low cost and small volume,therefore,it can increase the practicability of the system.In this investigation,the pH value was detected by the SnO_2/ITO glass-based pH sensor.During the signal progress,the detected signal was transferred to the microchip PIC18.After that,the microchip was able to communicate with PC by the Bluetooth.Moreover,the microchip can diagnose the sensing signal and sends the warning signal by alert function.In addition,the part of PC has the ability to record the information,builds the database for analyzing the pH values,and provides a better long-distance monitoring system.
文摘This paper presents the studying results of the sodium ion sensor device based on the SnO_2/ITO glass structure in the detection of rinsing solution for contact lenses.The selective membrane contains poly (vinyl chloride) (PVC),bis (2-ethylhexyl) sebacate (DOS),(12-crown-4) methylmalonate (B12C4),and sodium tetrakis (4-fluoropbenyl) borate dehydrate (NaTFBD). The final weight ratios are PVC:DOS:B12C4:NaTFBD=33:66:2:2.In this condition,the sensor has performances with linear sensitivity,short response time,good repeatability and selectivity.The sensor was used to measure the rinsing solution for the contact lenses.Because the experimental results show close to the accurate value for four commercial products,this sensor can preliminary be used in detecting the rinsing solution for the contact lenses.Using this structure and sodium-sensing membrane to construct the sodium sensor is proven successfully in this application.
