This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: What if signs of disease could be detected using nothing more than a tiny chip that fits in the palm of your hand and a camera, without ever visiting a hospital? A scene that once seemed possible only in science fiction has now moved one step closer to reality.
A research team led by Professor Junsuk Rho of the Departments of Mechanical Engineering, Chemical Engineering, Electrical Engineering, and the Graduate School of Convergence Science and Technology at POSTECH, together with Dr. Hongyoon Kim of the Department of Mechanical Engineering and Heechang Yun and Sebin Jeong of the Department of Chemical Engineering, has developed a metasurface biosensor capable of precisely detecting biomolecules through imaging without the need for an expensive spectrometer. The research was conducted in collaboration with Professor Hyomin Lee's group in the Department of Chemical Engineering at POSTECH and Professor Yong-Sang Ryu's group in the Department of Biomedical Engineering at Korea University.
The study was published in Nature Communications. Biosensors are essential tools in health care, with applications ranging from disease diagnosis and infectious disease testing to cancer biomarker detection and genetic analysis. Among them, optical biosensors offer a particularly important advantage.
They can directly detect biomolecules without fluorescent labels by measuring subtle optical changes that occur when target molecules bind to the sensor surface. The challenge, however, has been the size and complexity of conventional systems. Detecting such minute optical changes typically requires a high-resolution spectrometer together with a broadband light source.
Because these instruments are bulky and expensive, it has been difficult to bring high-performance optical biosensing beyond laboratories and hospitals. The POSTECH-led team approached the problem from a different perspective. Instead of measuring a spectrum with a spectrometer, they designed the sensor to convert spectral information into spatial information that can be directly read through imaging.
At the heart of the technology is a specially engineered continuous geometric-gradient metasurface. The nanoscale structures that make up the metasurface gradually change in geometry along one direction of the chip, causing different positions to respond to different wavelengths of light. Just as the keys of a piano produce different notes depending on their position, different locations on the metasurface resonate at different wavelengths.
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