Amperometric sensors based on tyrosinase-modified screen-printed arrays

Area of Science:

• Electrochemistry
• Biosensor Technology
• Biomaterials

Background:

• Tyrosinase biosensors are crucial for detecting phenolic compounds.
• Developing stable and sensitive enzyme immobilization techniques is key for biosensor performance.
• Screen-printed electrode arrays offer advantages in miniaturization and multi-analyte detection.

Purpose of the Study:

• To design and develop a novel amperometric screen-printed biosensor array modified with tyrosinase (polyphenol oxidase).
• To investigate and compare the performance of different electrode surfaces for enzyme immobilization.
• To evaluate the electrocatalytic characteristics, operational, and storage stability of the developed biosensor.

Main Methods:

• Fabrication of Au-screen-printed four-channel electrode arrays with different surface modifications (Au, graphite-coated-Au, Carbopack C-coated-Au).
• Immobilization of tyrosinase within a redox-hydrogel (PVI(13)-dmeOs polymer).
• Electrochemical characterization and stability testing using catechol as a model substrate.

Main Results:

• Carbopack C-coated electrode arrays demonstrated superior tyrosinase immobilization, mechanical stability, sensitivity, and stability up to 6 months.
• The biosensors exhibited a linear response to catechol up to 30 µM with a limit of detection of 0.14 µM.
• Direct electrochemical reaction reversibility of catechol was not a limiting factor for biosensor performance.

Conclusions:

• The Carbopack C-coated screen-printed biosensor array represents an effective platform for tyrosinase immobilization, offering enhanced stability and sensitivity.
• This biosensor is suitable for the reliable detection of phenolic compounds like catechol.
• The developed biosensor shows promising potential for practical applications requiring long-term stability.