Recently, a remarkable breakthrough has been made in the field of nanophotonic biosensing by the team led by Zhu Jinfeng from the College of Electronic Science and Technology at Xiamen University. This achievement was realized through collaboration with Wen Liaoyong's team from Westlake University, as well as with institutions such as Zhongshan Hospital of Fudan University and the First Affiliated Hospital of Xiamen University. Their groundbreaking research, entitled "Ultrasensitive biosensing by radiative Q-factor modulation in strongly coupled three-dimensional bound-state-in-the-continuum metasurfaces," was published in Nature Photonics and featured as the cover paper for the journal.

This study introduces a novel mechanism known as Q-modulated refractive index sensing (QMRS). It leverages strongly coupled three-dimensional bound-state-in-the-continuum metasurfaces to transform minute perturbations caused by biomolecular binding into significant shifts in the radiative quality Q-factor. This innovative approach substantially enhances light-matter interactions, surpassing the sensitivity constraints of conventional nanophotonic sensors.

The research team developed a wafer-level aluminum-based nanoimprinting process, facilitating the mass production of asymmetric three-dimensional nanometasurfaces. They also incorporated traditional LED broadband light sources and photodetectors to create a compact, palm-sized detection platform. This platform exhibited exceptional sensitivity in detecting extracellular vesicles from lung cancer cells, achieving a detection limit as low as 24 aM—approximately four orders of magnitude more sensitive than standard immunoassays.

In clinical tests involving 171 human serum samples, the platform attained an AUC of 94.9% for early-stage lung cancer detection and 92.1% for postoperative monitoring. This offers a new detection method for stratifying lung cancer risk and monitoring therapeutic effectiveness. Furthermore, this technology has vast potential applications and can be expanded into areas such as drug screening, disease diagnosis, and consumer electronics.