Carbon nanotube/polysulfone screen-printed electrochemical immunosensor

Area of Science:

• Materials Science
• Electrochemistry
• Biosensors

Background:

• Development of sensitive and efficient electrochemical immunosensors is crucial for diagnostics.
• Polysulfone membranes offer mechanical flexibility and high surface area for immobilization.
• Carbon nanomaterials can enhance transducer properties in biosensing applications.

Purpose of the Study:

• To develop a sensitive carbon nanotube/polysulfone/rabbit IgG (RIgG) immunocomposite.
• To create a modified disposable screen-printed electrochemical immunosensor.
• To evaluate the performance of the new immunosensor compared to graphite-based systems.

Main Methods:

• Fabrication of carbon nanotube/polysulfone membranes using a phase inversion method.
• Characterization using scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX), laser profilometry, and atomic force microscopy (AFM).
• Thermogravimetric analysis (TGA) for material purity assessment.
• Competitive assay using horse radish peroxidase (HRP) as a label and hydroquinone as a mediator.

Main Results:

• Carbon nanotube/polysulfone membranes exhibited significantly higher sensitivity than graphite/polysulfone membranes.
• Roughness of MWCNT-incorporated membranes was double that of graphite membranes, with antibody incorporation reducing roughness.
• The developed biosensor achieved a detection limit of 1.66 µg/ml for anti-RIgG, with a linear range of 2-5 µg/ml.
• Sensitivity was five times higher with MWCNT electrodes, demonstrating lower non-specific adsorption.

Conclusions:

• The carbon nanotube/polysulfone immunocomposite provides a simple, efficient, and highly sensitive platform for electrochemical immunosensors.
• The enhanced surface properties and transducer capabilities of carbon nanotubes improve biosensor performance.
• This approach offers a promising alternative for developing robust and sensitive diagnostic tools.