A WAVO3 pH electrode was prepared by a method of sol-gel. In order to study the H^＋ response dynamic mechanism, the electrochemical impedance spectroscopy （EIS） experiment was conducted. It was found that the H^＋ ...A WAVO3 pH electrode was prepared by a method of sol-gel. In order to study the H^＋ response dynamic mechanism, the electrochemical impedance spectroscopy （EIS） experiment was conducted. It was found that the H^＋ response course is controlled by the H^＋ diffusion from the solution to the WO3 film, based on the analysis of EIS spectra. The EIS and potential step method were used to determinate the H＋ diffusion coefficient （D） in the course of H^＋ response of this WAVO3 electrode, and the values of D calculated by these two method correspond very well, which all are about 10^-19cm^2/s The imposed different potential steps make little effect on the calculation of H^＋ diffusion coefficient, and it was found that the limiting Cottrell equation of short elapsed time fits well to the current transient caused by a potential step, based on the analysis of the time constant.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
A new approach named“caterpillar melt method”was developed to prepare wire type antimony oxide electrode for pH measurement in agar medium for tissue culture.A micro antimony wire was prepared from melt of the metal...A new approach named“caterpillar melt method”was developed to prepare wire type antimony oxide electrode for pH measurement in agar medium for tissue culture.A micro antimony wire was prepared from melt of the metal with the help of a glass capillary and the surface of the wire was oxidized in nitrate melt to obtain an antimony oxide electrode. Characterization results showed that the oxide layer is dense and uniform,with high physical and chemical stability.The electrode has a fast and stable response toward pH change for aqueous solutions.The potential of the antimony electrode has a linear relationship with the pH of the solution (R^2=1.00) with a sensitivity of 54.1mV/pH.The electrode works well and is more stable in agar medium during tissue culture for pH monitoring.展开更多
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
The potentials of Pt-black electrode using a copper conducting wire instead of the salt bridge in acid and alkaline solutions without the use of H2 evolution reactions were measured. There were three nonlinear portion...The potentials of Pt-black electrode using a copper conducting wire instead of the salt bridge in acid and alkaline solutions without the use of H2 evolution reactions were measured. There were three nonlinear portions in the calibration curve. Unusually, the potential slopes at pH 3-5 and 8-10 indicated 200 mV and 70 mV per pH, respectively. Such high sensitivity for pH slope, more than 4 times of usual 59 mV per pH, may be credited to the special properties of the Pt-black surface. SEM （scanning electronical microscopy） was applied to characterize the surface of the Pt-black electrode. Its working mechanism is well explained in the theory of capacitance potentials rather than Nernst＇s redox potentials.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
基金[This work was supported by the Science Foundation of Guangdong province of China (No. 05300370) and the Science Foundation of Foshan University.]
文摘A WAVO3 pH electrode was prepared by a method of sol-gel. In order to study the H^＋ response dynamic mechanism, the electrochemical impedance spectroscopy （EIS） experiment was conducted. It was found that the H^＋ response course is controlled by the H^＋ diffusion from the solution to the WO3 film, based on the analysis of EIS spectra. The EIS and potential step method were used to determinate the H＋ diffusion coefficient （D） in the course of H^＋ response of this WAVO3 electrode, and the values of D calculated by these two method correspond very well, which all are about 10^-19cm^2/s The imposed different potential steps make little effect on the calculation of H^＋ diffusion coefficient, and it was found that the limiting Cottrell equation of short elapsed time fits well to the current transient caused by a potential step, based on the analysis of the time constant.
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.
基金This project is sponsored by the Scientific Research Foundation for the Returned 0verseas Chinese Scholars；State EducationMinistry；the Zhejiang Natural Science Foundation under Grant No. Y404325.
文摘A new approach named“caterpillar melt method”was developed to prepare wire type antimony oxide electrode for pH measurement in agar medium for tissue culture.A micro antimony wire was prepared from melt of the metal with the help of a glass capillary and the surface of the wire was oxidized in nitrate melt to obtain an antimony oxide electrode. Characterization results showed that the oxide layer is dense and uniform,with high physical and chemical stability.The electrode has a fast and stable response toward pH change for aqueous solutions.The potential of the antimony electrode has a linear relationship with the pH of the solution (R^2=1.00) with a sensitivity of 54.1mV/pH.The electrode works well and is more stable in agar medium during tissue culture for pH monitoring.
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.
基金Funded by the Liaoning Province Education Science Foundation (No.2004D075)
文摘The potentials of Pt-black electrode using a copper conducting wire instead of the salt bridge in acid and alkaline solutions without the use of H2 evolution reactions were measured. There were three nonlinear portions in the calibration curve. Unusually, the potential slopes at pH 3-5 and 8-10 indicated 200 mV and 70 mV per pH, respectively. Such high sensitivity for pH slope, more than 4 times of usual 59 mV per pH, may be credited to the special properties of the Pt-black surface. SEM （scanning electronical microscopy） was applied to characterize the surface of the Pt-black electrode. Its working mechanism is well explained in the theory of capacitance potentials rather than Nernst＇s redox potentials.
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.
