Magnetic Detection Structure for Lab-on-Chip Applications Based on the Frequency Mixing Technique

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Analytical Chemistry

Background:

• Lab-on-Chip (LoC) systems offer miniaturized platforms for biological analyses.
• Accurate detection and quantification of superparamagnetic beads are crucial for various diagnostic assays.
• Existing methods for nanoparticle characterization can be complex and costly.

Purpose of the Study:

• To develop and validate a miniaturized magnetic frequency mixing technique for integrated LoC systems.
• To enable the detection and quantification of superparamagnetic beads for pathogen sensing and immunoassays.
• To investigate the design and performance of cost-effective planar spiral coils for magnetic sensing.

Main Methods:

• Analytical calculations and simulations were performed for miniaturized excitation and pick-up coils.
• A Printed Circuit Board (PCB) prototype was designed and manufactured.
• The prototype was tested for limit of detection, linear response, and theoretical concept validation.

Main Results:

• A limit of detection of 15 µg/mL for 20 nm core-sized nanoparticles was achieved using the magnetic frequency mixing technique.
• The system demonstrated linear response, validating the theoretical concepts.
• The developed planar coils were successfully miniaturized and integrated into a PCB prototype.

Conclusions:

• The magnetic frequency mixing technique is a viable method for integrated LoC pathogen sensing.
• Miniaturized planar coils enable cost-effective and sensitive detection of superparamagnetic beads.
• The system shows potential for advanced immunoassay applications and nanoparticle characterization.