Enzyme-sensing chitosan hydrogels

Area of Science:

• Biomaterials Science
• Biotechnology
• Analytical Chemistry

Background:

• Chitosan hydrogels are established wound dressing materials.
• Enzyme detection is crucial for monitoring wound infections.
• A need exists for rapid, sensitive biosensors integrated into wound dressings.

Purpose of the Study:

• To develop a chitosan hydrogel platform for enzyme detection.
• To functionalize chitosan with a fluorogenic substrate for signal generation.
• To demonstrate the platform's utility in detecting serine protease α-chymotrypsin.

Main Methods:

• Covalent conjugation of alanyl-alanyl-phenylalanine-7-amido-4-methylcoumarin (AAP-AMC) to chitosan.
• Fabrication of chitosan hydrogel thin films.
• Characterization of fluorescence emission upon enzymatic degradation.
• Optimization of hydrogel thickness, substrate loading, and enzyme concentration.

Main Results:

• The hydrogel platform successfully detected α-chymotrypsin via fluorescence increase.
• The release rate of 7-AMC correlated linearly with enzyme concentration and substrate loading.
• Detection limit for α-chymotrypsin was established at ≤10 nM within 5 minutes.
• Hydrogel thickness did not affect the initial release rate.

Conclusions:

• The developed chitosan hydrogel is a sensitive and rapid platform for enzyme detection.
• This technology holds promise for integration into smart wound dressings for infection sensing.
• The generic approach can be adapted for detecting various enzymes and pathogenic bacteria.