Printed Antifouling Electrodes for Biosensing Applications.

Area of Science:

• Electrochemistry
• Materials Science
• Biotechnology

Background:

• Biosensors using miniaturized electrodes show promise for point-of-care diagnostics.
• Electrochemical sensor performance is often limited by surface fouling in complex biological fluids.
• Existing composite coatings for antifouling require lengthy and complex fabrication processes, hindering commercialization.

Purpose of the Study:

• To develop a novel, rapidly fabricated, antifouling composite coating for electrochemical biosensors.
• To demonstrate the efficacy of the coating in preventing protein fouling and maintaining sensor performance.
• To enable the sensitive detection of biomarkers in undiluted biological samples.

Main Methods:

• A photoreactive antifouling copolymer and carbon nanotubes (CNTs) were combined into an ink for printing onto screen-printed electrodes.
• Cyclic voltammetry (CV) and protein fouling experiments were used to characterize the coating's electroactive surface area (EASA) and antifouling properties.
• Antibodies against C-reactive protein (CRP) were photochemically immobilized onto the functionalized electrodes for sandwich-immunoassay detection.

Main Results:

• The polymer/CNT composite coating exhibited an EASA comparable to uncoated electrodes.
• The coating retained over 90% of its initial EASA after 1 hour in concentrated bovine serum albumin solution, while uncoated electrodes lost over 80%.
• The fabricated biosensors successfully quantified nanogram-range concentrations of CRP in undiluted human blood serum.

Conclusions:

• A fast (<2 h), scalable printing process for antifouling polymer/CNT composite coatings was established.
• The developed coating effectively prevents biofouling and maintains electrochemical sensor performance in complex biological matrices.
• This platform demonstrates significant potential for developing sensitive and robust electrochemical biosensors for point-of-care applications.