Microfluidic based immunosensor for detection and purification of carbonylated proteins

Area of Science:

• Biotechnology
• Proteomics
• Microfluidics

Background:

• Low-abundance post-translational modification (PTM) proteins are crucial biomarkers for age-related diseases.
• Existing methods for protein enrichment are often time-consuming and lack sensitivity.
• Developing rapid and sensitive enrichment techniques is vital for early disease detection and therapeutic development.

Purpose of the Study:

• To design and fabricate an immunoaffinity-based microfluidic device for specific enrichment of carbonylated proteins.
• To evaluate the efficiency and specificity of the developed micro-device for trapping low-abundance PTM proteins.
• To demonstrate the potential of this micro-device for biomarker discovery in age-related diseases.

Main Methods:

• Development of a polydimethylsiloxane (PDMS) micro-device utilizing an immuno-precipitation approach.
• Chemical modification of the PDMS substrate with glutaraldehyde and antibodies for specific protein capture.
• Surface characterization using atomic force microscopy and fluorescence microscopy.
• Quantitative analysis of protein capture and elution efficiency using model proteins.

Main Results:

• The immunoaffinity micro-device demonstrated high sensitivity and specificity for carbonylated proteins in a complex mixture.
• Successful enrichment of low-abundance carbonylated proteins (159 ng of cytochrome c) within 110 minutes at a flow rate of 5 μL/min.
• Validation of the device's capability to specifically trap target proteins while excluding larger blocking proteins.

Conclusions:

• The developed micro-immunoprecipitation (μ-IP) method offers a fast and sensitive approach for enriching low-abundance PTM biomarkers.
• This technology holds significant promise for advancing early disease detection and therapeutic development in age-related diseases.
• The immuno-based microchip platform can be adapted for enriching other PTMs by utilizing different antibody groups.