Quinone-rich poly(dopamine) magnetic nanoparticles for biosensor applications

Area of Science:

• Nanotechnology
• Biomaterials
• Electrochemistry

Background:

• Development of advanced nanomaterials for biosensing applications.
• Poly(dopamine) coatings offer versatile functionalization for biomolecules.
• Magnetic nanoparticles (MNPs) provide ease of manipulation and separation.

Purpose of the Study:

• To synthesize novel quinone-rich poly(dopamine)-magnetic nanoparticles (MNPs).
• To immobilize glucose oxidase (Gox) onto these functionalized MNPs.
• To develop a highly sensitive and stable amperometric biosensor for glucose detection.

Main Methods:

• In situ polymerization to create core-shell MNPs with oxidized catechol groups.
• Characterization using XRD, XPS, AFM, MFM, UV/Vis, FTIR, and electrochemical techniques.
• Covalent immobilization of Gox via Schiff base formation and Michael addition.

Main Results:

• Successfully synthesized core-shell MNPs with a 17 nm core and 2 nm polymer film.
• Achieved significantly higher Gox immobilization (nearly double) on oxidized MNPs.
• Developed an amperometric glucose biosensor with 8.7 mA M⁻¹ cm⁻² sensitivity, 0.02 mM LOD, and 45-day stability.

Conclusions:

• Quinone-rich poly(dopamine)-MNPs serve as effective supports for enzyme immobilization.
• The developed Gox-MNP biosensor demonstrates excellent performance for glucose determination.
• The biosensor shows potential for reliable glucose monitoring in real blood samples.