scholarly journals Valve-Actuator-Integrated Reference Electrode for an Ultra-Long-Life Rumen pH Sensor

Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1249
Author(s):  
Shogo Higuchi ◽  
Hironao Okada ◽  
Seiichi Takamatsu ◽  
Toshihiro Itoh
Keyword(s):  
Ph Monitoring ◽  
Ph Sensor ◽  
Reference Electrode ◽  
Ph Sensors ◽  
Liquid Junction ◽  
Reference Electrodes ◽  
Potential Measurement ◽  
Rumen Ph ◽  
Long Life ◽  
Intermittent Measurement

We demonstrated a newly developed Ag/AgCl reference electrode- with a valve-actuator for two years or longer rumen pH monitoring. Previous studies on pH sensors reported that the short lifetime of Ag/AgCl reference electrodes is caused by an outflow of internal electrolyte. We introduced a valve-actuator into a liquid junction to reduce the outflow by intermittent measurement. The results indicated that the potential change when switching the liquid junction was less than 0.5 mV and its response time was less than 0.083 s. In the 24-h potential measurement with the valve-actuator-integrated reference electrode (VAIRE), the valve was actuated once every hour, and the standard deviation of the potential was 0.29 mV. The lifetime of the VAIRE was estimated at 2.0 years calculating from an electrolyte outflow, which is significantly longer than that of conventional reference electrodes. A pH sensor using the VAIRE was estimated to operate for 2.0 years with the pH error ≤0.1, which meets the requirement of cows’ rumen pH monitoring.

scholarly journals Titanium Nitride Thin Film Based Low-Redox-Interference Potentiometric pH Sensing Electrodes

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 42
Author(s):  
Shimrith Paul Shylendra ◽  
Wade Lonsdale ◽  
Magdalena Wajrak ◽  
Mohammad Nur-E-Alam ◽  
Kamal Alameh
Keyword(s):  
Thin Film ◽  
Titanium Nitride ◽  
Orange Juice ◽  
Ph Sensor ◽  
Reference Electrode ◽  
Cost Effective ◽  
Ph Sensing ◽  
Ph Sensors ◽  
Potential Shift ◽  
Double Junction

In this work, a solid-state potentiometric pH sensor is designed by incorporating a thin film of Radio Frequency Magnetron Sputtered (RFMS) Titanium Nitride (TiN) working electrode and a commercial Ag|AgCl|KCl double junction reference electrode. The sensor shows a linear pH slope of −59.1 mV/pH, R2 = 0.9997, a hysteresis as low as 1.2 mV, and drift below 3.9 mV/h. In addition, the redox interference performance of TiN electrodes is compared with that of Iridium Oxide (IrO2) counterparts. Experimental results show −32 mV potential shift (E0 value) in 1 mM ascorbic acid (reducing agent) for TiN electrodes, and this is significantly lower than the −114 mV potential shift of IrO2 electrodes with sub-Nernstian sensitivity. These results are most encouraging and pave the way towards the development of miniaturized, cost-effective, and robust pH sensors for difficult matrices, such as wine and fresh orange juice.

scholarly journals Influence of Erythrocytes on Direct Potentiometric Determination of Sodium and Potassium

1983 ◽  
Vol 20 (2) ◽  
pp. 116-120 ◽  
Author(s):  
P Bijster ◽  
H L Vader ◽  
C L J Vink
Keyword(s):  
Whole Blood ◽  
Potassium Concentration ◽  
Reference Electrode ◽  
Sodium Concentration ◽  
General Phenomenon ◽  
Liquid Junction ◽  
Direct Potentiometry ◽  
The Difference ◽  
Sodium And Potassium

We have shown that the sodium concentration in whole blood measured by direct potentiometry is higher than in plasma. The ‘erythrocyte-effect’, already described by Siggaard Andersen, is most pronounced for instruments equipped with a reference electrode with an open static liquid junction and is thus a general phenomenon. Instruments with a modified liquid junction show less interference. The same phenomenon appears for the determination of the potassium concentration, although the difference between whole blood and plasma, when measured with instruments equipped with a modified liquid junction, can be neglected in practice.

Poly Silk Peptide Film PH Sensor Based on Zero Current Potentiometry

2012 ◽  
Vol 450-451 ◽  
pp. 554-556
Author(s):  
Ming Ming Ma ◽  
Zhi Tong ◽  
Yong Wen
Keyword(s):  
Graphite Electrode ◽  
Ph Sensor ◽  
Reference Electrode ◽  
Pencil Graphite Electrode ◽  
Solution Ph ◽  
Counter Electrodes ◽  
System A ◽  
Zero Current ◽  
In Series ◽  
Silk Peptide

A poly silk peptide film pH sensor has been developed using zero current potentiometry system. A poly silk peptide film coated pencil graphite electrode is connected in series between the working and counter electrodes of a potentiostat, and immersed in solution together with a reference electrode. When the solution pH varies, the resulting zero current potentiometry is linear with the values of the solution pH in the range of 1.81 to 11.58. This pH sensor shows high stability, accuracy, selectivity and reproduction.

scholarly journals Visual pH Sensors: From a Chemical Perspective to New Bioengineered Materials

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2952
Author(s):  
Luigi Di Costanzo ◽  
Barbara Panunzi
Keyword(s):  
Ph Monitoring ◽  
Three Dimensional ◽  
Lessons Learned ◽  
Background Information ◽  
Biological Macromolecules ◽  
Ph Sensing ◽  
Ph Sensors ◽  
Cellular Functions ◽  
Metal Organic

Many human activities and cellular functions depend upon precise pH values, and pH monitoring is considered a fundamental task. Colorimetric and fluorescence sensors for pH measurements are chemical and biochemical tools able to sense protons and produce a visible signal. These pH sensors are gaining widespread attention as non-destructive tools, visible to the human eye, that are capable of a real-time and in-situ response. Optical “visual” sensors are expanding researchers’ interests in many chemical contexts and are routinely used for biological, environmental, and medical applications. In this review we provide an overview of trending colorimetric, fluorescent, or dual-mode responsive visual pH sensors. These sensors include molecular synthetic organic sensors, metal organic frameworks (MOF), engineered sensing nanomaterials, and bioengineered sensors. We review different typological chemical entities of visual pH sensors, three-dimensional structures, and signaling mechanisms for pH sensing and applications; developed in the past five years. The progression of this review from simple organic molecules to biological macromolecules seeks to benefit beginners and scientists embarking on a project of pH sensing development, who needs background information and a quick update on advances in the field. Lessons learned from these tools will aid pH determination projects and provide new ways of thinking for cell bioimaging or other cutting-edge in vivo applications.

scholarly journals Ruthenium Oxide pH Sensing for Organs-On-Chip Studies

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 709 ◽  
Author(s):  
Esther Tanumihardja ◽  
Wouter Olthuis ◽  
Albert van den Berg
Keyword(s):  
Ph Sensor ◽  
Ruthenium Oxide ◽  
Open Circuit ◽  
Biological Medium ◽  
Similar Response ◽  
Ph Sensing ◽  
Ph Sensors ◽  
Cross Sensitivity ◽  
On Chip

A ruthenium oxide (RuOx) electrode is being developed as potentiometric pH sensor for organs-on-chip applications. Open-circuit potential (OCP) of the RuOx electrode showed a response of −58.05 mV/pH, with no cross-sensitivity to potentially interfering/complexing ions (tested were lithium, sulfate, chloride, and calcium ions). Similar response was observed in complex biological medium. The electrode stored in liquid had a long-term drift of −0.8 mV/hour (corresponding to ΔpH of 0.013/hour) and response time in complex biological medium was 3.7 s. Minimum cross-sensitivity to oxygen was observed as the OCP shifted ~3 mV going from deoxygenated to oxygenated solution. This response is one magnitude lower than previously reported for metal- oxide pH sensors. Overall, the RuOx pH sensor has proven to be a suitable pH sensor for organs- on-chip applications.

Guidelines for potentiometric measurements in suspensions Part B. Guidelines for practical pH measurements in soil suspensions (IUPAC Recommendations 2006)

2007 ◽  
Vol 79 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Srecko F. Oman ◽  
M. Filomena Camões ◽  
Kipton J. Powell ◽  
Raj Rajagopalan ◽  
Petra Spitzer
Keyword(s):  
Reference Electrode ◽  
Operational Definition ◽  
Indicator Electrode ◽  
Liquid Junction ◽  
Cell Potential ◽  
Technical Report ◽  
Potentiometric Measurements ◽  
Suspension Effect ◽  
The Difference ◽  
Definition Of

The measured cell potentials for suspension potentiometric cells have been interpreted and explained by a detailed analysis of the schemes for these cells ["Guidelines for potentiometric measurements in suspensions. Part A. The suspension effect (IUPAC Technical Report", Pure Appl. Chem.79, 67 (2007)]. Some former disagreements amongst investigations have been clarified. A new unambiguous operational definition of the suspension effect (SE) is presented. It is defined as the difference in cell potential for two suspension potentiometric cells, one with both electrodes in the separated equilibrium solution (eqs) and the other with both electrodes in the sediment or suspension. This potential difference is the sum of the change in the indicator electrode (IE) potential and the change in the liquid junction potential of the reference electrode (RE), when the electrodes are used for measurement, once in the sediment of the suspension and then in its eqs.

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