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PCB-Based Magnetometer as a Platform for Quantification of Lateral-Flow Assays
Mohammad Khodadadi1,2, Long Chang1,3, João R C Trabuco4,5
1Center for Integrated Bio & Nano Systems, University of Houston, Houston, TX 77204, USA.
Sensors (Basel, Switzerland)
|December 15, 2019
Summary
A new inductive transducer, femtoMag, enables precise quantification of biomarkers on lateral-flow assays (LFAs). This low-cost technology achieves high sensitivity for molecular diagnostics, bringing advanced tests to point-of-care settings.
Area of Science:
- Biomedical Engineering
- Nanotechnology
- Assay Development
Background:
- Lateral-flow assays (LFAs) are widely used for rapid diagnostics but often lack precise quantification capabilities.
- Existing methods for quantifying nanoparticle reporters in LFAs can be complex or expensive.
- There is a need for cost-effective, high-precision detection platforms for molecular biomarkers.
Purpose of the Study:
- To demonstrate a novel inductive transducer, the femtoMag, for integrated detection and quantification in LFAs.
- To develop a low-cost, high-precision platform for measuring superparamagnetic nanoparticle reporters.
- To assess the femtoMag's performance in quantifying a specific molecular biomarker, the hCG hormone.
Main Methods:
- Manufactured an inductive transducer (femtoMag) using printed circuit board (PCB) technology.
- Integrated the femtoMag with a lateral-flow assay (LFA) strip containing superparamagnetic nanoparticle reporters.
- Quantified the number of nanoparticle reporters immuno-captured on the LFA test line using the femtoMag transducer.
- Validated the system by quantifying human chorionic gonadotropin (hCG) hormone concentrations.
Main Results:
- The femtoMag achieved a detection limit of 10-10 emu, equivalent to 4 ng of Fe3O4 nanoparticles.
- Demonstrated a sensitivity of 100 pg/mL for hCG quantification, with a projected sensitivity better than 10 pg/mL.
- Showcased a monotonic increase in the ratio of hCG molecules to nanoparticle reporters with increasing hCG concentration.
- Confirmed the platform's ability to quantify nanoparticle reporters along the entire LFA test strip.
Conclusions:
- The femtoMag transducer offers a low-cost, high-sensitivity, and high-precision solution for quantifying molecular biomarkers in LFAs.
- This technology has the potential to significantly enhance the capabilities of point-of-care diagnostic tests.
- Further improvements in design and electronics are expected to yield even greater sensitivity, broadening its diagnostic applications.
