Polypyrrole-Coated Microneedle Platform for Offline Electrochemical Detection of Interferon-Alpha in Interstitial...

Area of Science:

• Biomedical Engineering
• Biosensor Technology
• Immunology

Background:

• Monitoring cytokines like interferon-alpha (IFN-α) is crucial for evaluating immune status in viral infections and immunotherapy.
• Current methods for cytokine detection can be invasive or require complex laboratory equipment.
• There is a need for minimally invasive, point-of-care diagnostic tools for real-time immune monitoring.

Purpose of the Study:

• To develop and characterize a microneedle-based electrochemical biosensor for label-free, offline detection of IFN-α in interstitial fluid (ISF).
• To optimize the biosensor's performance by evaluating different polypyrrole (PPy) coating concentrations on polycaprolactone (PCL) microneedles.
• To assess the biosensor's sensitivity, specificity, and biocompatibility for potential use in diagnostics.

Main Methods:

• Fabrication of PCL microneedles using 3D-printed molds and thermocompression.
• Coating microneedles with varying concentrations of polypyrrole (PPy) to enhance conductivity and biomolecule immobilization.
• Characterization of microneedle surface properties (roughness, porosity) and electrochemical performance using techniques like electrochemical impedance spectroscopy and cyclic voltammetry.
• Evaluation of IFN-α detection limits, linearity, selectivity, and cytotoxicity.

Main Results:

• Optimized PPy concentration (50 mmol·L⁻¹) yielded ideal surface properties (29.7% porosity) and electroactive area while maintaining mechanical integrity.
• The biosensor demonstrated sensitive and specific IFN-α detection with a limit of detection of 8.6 pg/mL and a linear range up to 1000 pg/mL.
• Selectivity and cytotoxicity assays confirmed the biosensor's robust performance and safety for biological applications.

Conclusions:

• The developed PPy-coated microneedle biosensor provides a minimally invasive and label-free platform for IFN-α detection in ISF.
• This technology holds significant potential for cost-effective, scalable, and convenient cytokine monitoring in point-of-care diagnostic settings.
• The study highlights the utility of microneedle arrays for advancing personalized medicine and rapid diagnostics.