Nitrite electrochemical biosensing based on coupled graphene and gold nanoparticles

Area of Science:

• Electrochemistry
• Nanomaterials Science
• Biosensor Technology

Background:

• Graphene-gold nanoparticle (AuNP) hybrids offer unique electrochemical properties.
• Immobilization of hemoglobin (Hb) on such composites can create sensitive biosensing platforms.
• Accurate nitrite determination is crucial for food safety.

Purpose of the Study:

• To develop a facile method for preparing graphene-AuNP hybrids.
• To fabricate and characterize a novel biosensor for nitrite detection using Hb immobilized on graphene-AuNP composites.
• To evaluate the performance and applicability of the developed biosensor for nitrite determination in food samples.

Main Methods:

• In situ growth of AuNPs on graphene nanosheets for hybrid formation.
• Immobilization of hemoglobin (Hb) onto the graphene-AuNP composites.
• Electrochemical characterization and performance evaluation of the fabricated biosensor.
• Nitrite determination in pickled radish samples and comparison with standard methods.

Main Results:

• Homogeneously distributed AuNPs on graphene nanosheets were successfully prepared.
• The Hb/graphene-AuNP biosensor exhibited well-defined redox peaks at -0.314 V.
• The biosensor demonstrated a wide linear range (0.05–1000 µM), low detection limit (0.01 µM), high sensitivity (0.15 μA μM⁻¹ cm⁻²), and excellent selectivity.
• Nitrite levels in pickled radish determined by the biosensor showed good agreement with spectrophotometric methods.

Conclusions:

• A novel and sensitive biosensor based on Hb/graphene-AuNP hybrids was successfully developed.
• The biosensor offers significant advantages in terms of sensitivity, selectivity, and response range for nitrite detection.
• The developed biosensor shows promising practical application for accurate nitrite determination in food products, contributing to food safety standards.