Sensitive amperometric biosensor for phenolic compounds based on graphene-silk peptide/tyrosinase composite...

Area of Science:

• Nanoscience and Nanotechnology
• Biotechnology
• Analytical Chemistry

Background:

• Phenolic compounds are widespread environmental contaminants.
• Developing sensitive and selective biosensors is crucial for their detection.
• Graphene and silk peptides offer promising nanomaterials for biosensor fabrication.

Purpose of the Study:

• To develop a novel biosensor for the determination of phenolic compounds.
• To fabricate and characterize graphene-silk peptide (Gr-SP) nanosheets.
• To immobilize tyrosinase (Tyr) onto Gr-SP nanosheets for enhanced biosensing performance.

Main Methods:

• Preparation and characterization of Gr-SP nanosheets using TEM, XRD, and XPS.
• Fabrication of the Gr-SP-Tyr biosensor and characterization using SEM and EIS.
• Optimization of biosensor parameters including Gr-SP-Tyr volume, applied potential, pH, temperature, and Tyr/Gr-SP ratio.
• Electrochemical determination of catechol, phenol, and bisphenol A (BPA).

Main Results:

• The Gr-SP-Tyr biosensor demonstrated excellent sensitivity for catechol (7634 mA M⁻¹cm⁻²), phenol (4082 mA M⁻¹cm⁻²), and BPA (2511 mA M⁻¹cm⁻²).
• Low detection limits were achieved: 0.23 nM for catechol, 0.35 nM for phenol, and 0.72 nM for BPA.
• The biosensor exhibited good repeatability, long-term stability, and was successfully applied to detect BPA leaching from plastic bottles.

Conclusions:

• The developed Gr-SP-Tyr biosensor is a highly sensitive and stable platform for detecting phenolic compounds.
• This novel biosensor holds potential for environmental monitoring and food safety applications.
• The combination of graphene-silk peptide and tyrosinase offers a promising strategy for advanced biosensor development.