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Highly Stable Potentiometric (Bio)Sensor for Urea and Urease Activity Determination
Marcin Urbanowicz1, Kamila Sadowska1, Agnieszka Paziewska-Nowak1
1Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Ks. Trojdena 4, 02-109 Warsaw, Poland.
Membranes
|November 27, 2021
Summary
A novel, stable potentiometric sensor was developed for determining urease activity and urea levels. This bioanalytical tool demonstrates excellent stability and rapid response, proving effective for analyzing human saliva samples.
Area of Science:
- Electrochemistry
- Biosensor Technology
- Analytical Chemistry
Background:
- Growing demand for user-specific bioanalytical tools for research.
- Need for stable and efficient sensors for enzyme activity and analyte determination.
Purpose of the Study:
- Develop a highly stable potentiometric sensor for urease activity determination.
- Create a urea biosensor by biofunctionalizing an ammonium ion-selective sensor.
- Investigate the electrical properties of the ion-to-electron transducing layer.
Main Methods:
- Development of a potentiometric sensor using glassy carbon/polyazulene/NH4+-selective membrane.
- Urease-urea interaction studies to establish the Michaelis-Menten constant.
- Impedance spectroscopy to analyze electrical properties of the polyazulene layer.
Main Results:
- The developed urea biosensor exhibited excellent potential stability (~0.9 mV/h) and a short response time (36 s).
- Nernstian response (52.4 ± 0.7 mV/dec) observed for urea concentrations from 0.01 to 20 mM, stable for 60 days.
- Polyazulene layer showed minimal capacitive behavior, contributing to sensor stability.
- Successful determination of ammonium ion and urea in human saliva samples, validated by spectrophotometric methods.
Conclusions:
- The developed polyazulene-based sensor offers a stable and reliable platform for potentiometric measurements.
- The urea biosensor is effective for determining urea concentrations in biological samples like saliva.
- The study provides insights into sensor design for enhanced stability and performance in bioanalytical applications.
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