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Updated: Jun 25, 2026
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Ultrasensitive Detection of Biomarkers by Using a Molecular Imprinting Based Capacitive Biosensor
Published on: February 16, 2018
Direct imaging-based gradient metasurface sensor enabling spectrometer-free ultrasensitive biomolecule detection
Hongyoon Kim1, Heechang Yun2,3, Sebin Jeong2
1Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea.
Nature Communications
|June 23, 2026
Summary
We developed a novel direct imaging biosensor that reconstructs spectral shifts without a spectrometer. This compact, label-free platform enables sensitive protein and DNA detection for accessible diagnostics.
Area of Science:
- Nanotechnology
- Optical Engineering
- Biomedical Diagnostics
Background:
- Biosensors are vital for rapid, on-site diagnostics.
- Current optical biosensors often require complex spectroscopic instrumentation.
- There is a need for simplified, portable, and cost-effective biosensing solutions.
Purpose of the Study:
- To introduce a direct imaging-based biosensor that eliminates the need for a spectrometer.
- To demonstrate a novel metasurface design for spatial encoding of wavelengths.
- To enable sensitive, label-free molecular detection with a simplified optical setup.
Main Methods:
- Fabrication of a dielectric metasurface with a continuous geometry gradient.
- Spatially encoding distinct resonance wavelengths across the metasurface.
- Reconstructing spectral shifts from transmission images using a single camera.
Main Results:
- Achieved a high-quality factor and 0.1 nm spectral step size over a 30 nm window.
- Demonstrated a compact 300 µm footprint without spectroscopic instrumentation.
- Exhibited high sensitivity (FOM = 67.2 RIU) and label-free detection of proteins and DNA down to 388 pM.
Conclusions:
- The spectrometer-free biosensor offers a compact and sensitive platform for molecular testing.
- The direct imaging approach simplifies optical architecture, paving the way for cost-effective diagnostics.
- This technology facilitates molecular testing outside specialized laboratory settings.
