Researchers at Tianjin University of Technology, led by young faculty member Li Pei from the School of Integrated Circuit Science and Engineering, in collaboration with the University of Science and Technology of China, Beijing Computational Science Research Center, and Wigner Research Centre for Physics in Hungary, have achieved a significant breakthrough in quantum sensing technology, laying a theoretical foundation for its application in life sciences. The findings were published in the international journal Nature Materials.
Quantum sensors, known as “nanoscale stethoscopes” due to their ultra-high magnetic field sensitivity, can capture extremely weak magnetic signals, showing great potential in medical diagnostics and life science research. The most widely used sensor is the diamond nitrogen–vacancy (NV) center quantum sensor. While it operates at room temperature, it requires 532 nm green light excitation. This wavelength is easily absorbed by water and organic molecules in biological tissue, causing spontaneous tissue fluorescence and local heating, which severely interferes with detection signals and limits in vivo applications.
To address this, the team turned to the mature semiconductor material silicon carbide (SiC). They innovatively applied a low-temperature olefin molecular chemical modification to construct an organic carbon chain protective layer on the SiC surface, effectively creating a “protective suit” for the quantum sensor. This layer suppresses surface trap states’ interference on the color center qubits while maintaining the material’s electrical structure stability. Experiments confirmed significant improvement in qubit decoherence and fluorescence blinking, resulting in more stable and reliable sensor performance.
Using this surface molecular engineering, the team built a room-temperature, biologically inert quantum sensing platform. Its excitation and emission bands are within the near-infrared biological window, offering low absorption and low background fluorescence, suitable for non-invasive magnetic field detection in complex biological environments, with high sensitivity to local electron spin noise.
This research enhances quantum sensor sensitivity and stability and opens a key pathway for quantum technology in biomedical applications. After optimization, the technology can be applied to quantum nuclear magnetic resonance detection, single-molecule magnetic resonance imaging, radical detection, and other cutting-edge fields, potentially enabling real-time monitoring of cellular-level lesions and in vivo drug tracking for precision medicine.
Li Pei stated that introducing molecular-level interface engineering into quantum sensor design is an important development direction, improving device stability at room temperature and better adapting quantum sensing to real biological environments. This method provides a feasible path for room-temperature biological quantum sensing and offers new design ideas for interface engineering in wide-bandgap semiconductor quantum devices.
source: Chen Xi, Science and Technology Daily