A digital microfluidic device with integrated nanostructured microelectrodes for electrochemical immunoassays

Area of Science:

• Electrochemistry
• Microfluidics
• Biosensing

Background:

• Nanostructured microelectrodes (NMEs) provide excellent sensitivity for electroanalysis.
• Digital microfluidics (DMF) is a versatile platform for fluid handling.
• Integrating NMEs with DMF enables advanced analytical capabilities.

Purpose of the Study:

• To integrate NMEs with DMF for distributed diagnostics.
• To evaluate the performance of the integrated NME-DMF system.
• To develop a rubella virus IgG immunoassay using the new system.

Main Methods:

• Modification of indium tin oxide DMF top plates with gold (Au) NMEs, counter, and pseudoreference electrodes.
• Development of a rubella virus (RV) IgG immunoassay using magnetic microparticles.
• Analysis of immunoassay results via differential pulse voltammetry.

Main Results:

• The integrated NME-DMF system outperformed traditional planar sensing electrodes on DMF.
• The rubella virus IgG immunoassay achieved a limit of detection of 0.07 IU mL(-1).
• The assay's sensitivity was over 100 times lower than the WHO cut-off for rubella immunity.

Conclusions:

• The integrated NME-DMF system offers high sensitivity and small size for electroanalysis.
• The system shows significant potential for distributed diagnostic applications.
• This technology advances point-of-care testing capabilities.