Highly Sensitive and Quantitative Magnetic Nanoparticle-Based Lateral Flow Immunoassay with an Atomic Magnetometer

Area of Science:

• Quantum sensing
• Biosensing technology
• Nanoparticle-based assays

Background:

• Lateral flow immunoassays (LFIA) are point-of-care diagnostics but suffer from poor quantification and precision.
• Magnetic nanoparticles (MNPs) enhance LFIA sensitivity, yet quantitative detection of trace biomarkers needs improvement.
• Existing magnetic detection methods for MNPs in LFIA are complex or lack sufficient sensitivity.

Purpose of the Study:

• To develop a real-time biosensing platform for quantitative detection in MNP-based LFIA.
• To enhance the precision and quantification capabilities of LFIA using atomic magnetometer technology.
• To establish a reliable method for detecting trace biomarkers with improved sensitivity.

Main Methods:

• Proposed a real-time biosensing platform utilizing a highly sensitive atomic magnetometer.
• Employed continuous, linear scanning of trace MNP labels to obtain residual flux density component spectra.
• Utilized a theoretical magnetic dipole model to verify the reliability of spectral analysis for quantification.

Main Results:

• Demonstrated a 100-fold enhancement in detection factor compared to optical methods for carcinoembryonic antigen (CEA).
• Achieved a low detection limit of approximately 0.01 ng mL⁻¹ for CEA.
• Presented a more straightforward detection mechanism than other magnetic detection approaches.

Conclusions:

• The atomic magnetometer platform offers superior sensitivity and quantification for MNP-based LFIA.
• This technology significantly overcomes the limitations of traditional LFIA methods.
• Results highlight the potential of atomic magnetometer quantum measurement techniques in intelligent diagnostics.