A method to construct a third-generation horseradish peroxidase biosensor: self-assembling gold nanoparticles to...

Area of Science:

• Electrochemistry
• Nanomaterials Science
• Biotechnology

Background:

• Biosensors are crucial for detecting various analytes.
• Horseradish peroxidase (HRP) is a key enzyme in biosensing applications.
• Developing efficient fabrication methods for HRP biosensors is an active research area.

Purpose of the Study:

• To develop a novel method for fabricating a horseradish peroxidase (HRP) biosensor.
• To investigate the self-assembly of gold nanoparticles onto a thiol-containing sol-gel network for HRP immobilization.
• To characterize the electrochemical performance of the developed HRP biosensor.

Main Methods:

• Fabrication of a three-dimensional silica gel network on a gold electrode using (3-mercaptopropyl)-trimethoxysilane (MPS).
• Chemisorption of gold nanoparticles onto the thiol groups of the sol-gel network.
• Immobilization of horseradish peroxidase (HRP) onto the gold nanoparticle surface.
• Electrochemical characterization using techniques like atomic force microscopy (AFM).

Main Results:

• Successful self-assembly of gold nanoparticles and HRP onto the sol-gel network was confirmed by AFM.
• The immobilized HRP exhibited direct electrochemical behavior for hydrogen peroxide reduction.
• The biosensor achieved a fast amperometric response time of 2.5 seconds.
• A low detection limit of 2.0 µmol L⁻¹ and a wide linear range (5.0 µmol L⁻¹ to 10.0 mmol L⁻¹) were obtained.
• The biosensor demonstrated high sensitivity, good reproducibility, and long-term stability.

Conclusions:

• A novel and effective method for HRP biosensor fabrication using gold nanoparticle-functionalized sol-gel has been established.
• The developed biosensor shows excellent performance characteristics, including rapid response, high sensitivity, and stability.
• This approach offers a promising platform for sensitive and reliable electrochemical detection of hydrogen peroxide.