Potentiometric determination of trypsin using a polymeric membrane polycation-sensitive electrode based on...

Area of Science:

• Analytical Chemistry
• Biochemistry
• Biosensor Technology

Background:

• Protease activity, particularly trypsin, is crucial in biological processes and disease diagnostics.
• Accurate and rapid detection methods for proteases are essential for research and clinical applications.
• Existing methods for protease detection can be time-consuming or require specific reagents.

Purpose of the Study:

• To develop a novel potentiometric biosensor for the sensitive and selective determination of trypsin.
• To investigate a current-controlled reagent delivery system for in situ protamine generation.
• To explore the application of this biosensor in reagentless detection of protease activities.

Main Methods:

• Fabrication of a protamine-sensitive electrode with a polymeric membrane and dinonylnaphthalene sulfonate.
• Utilizing current-controlled diffusion of protamine across the membrane for reagent delivery.
• Monitoring changes in membrane potential due to trypsin-catalyzed hydrolysis of protamine.
• Optimizing parameters such as anodic current amplitude, pulse duration, and protamine concentration.

Main Results:

• The biosensor demonstrated continuous and reversible detection of trypsin.
• Achieved a trypsin detection range of 0.5-5 U/mL with a detection limit of 0.3 U/mL.
• The system proved to be rapid and reagentless, relying on potentiometric measurements.

Conclusions:

• The developed potentiometric biosensor offers a sensitive and efficient method for trypsin determination.
• The current-controlled reagent delivery system provides precise control over protamine release.
• This approach holds significant potential for homogeneous immunoassays utilizing proteases as labels.