A Microfluidic Chip-Based MRS Immunosensor for Biomarker Detection via Enzyme-Mediated Nanoparticle Assembly

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Conventional immunoassays for whole blood present challenges with complex procedures and limited sensitivity.
• There is a need for more efficient and sensitive diagnostic tools for whole blood analysis.

Purpose of the Study:

• To develop a microfluidic chip-based magnetic relaxation switching (MRS) immunosensor for simplified and sensitive detection in whole blood.
• To overcome the limitations of traditional immunoassay methods.

Main Methods:

• Enzyme-mediated nanoparticles were utilized for signal amplification.
• A silver mirror reaction catalyzed by catalase controlled silver nanoparticle (Ag NP) production.
• Ag NP formation influenced magnetic nanoparticle (MNP) aggregation, altering transverse relaxation time (T2).
• All reactions were performed on a microfluidic chip to reduce time and reagent use.

Main Results:

• The MRS immunosensor demonstrated a sensitive detection of alpha-fetoprotein (AFP) in real samples.
• Achieved a limit of detection (LOD) of 0.56 ng/ml for AFP.
• The method proved superior to conventional ELISA in terms of sensitivity.

Conclusions:

• The microfluidic MRS immunosensor offers a promising platform for rapid and sensitive whole blood diagnostics.
• This approach simplifies assay procedures and enhances detection limits.
• The technology holds potential for improved clinical biomarker analysis.