Work

Ultrasensitive metasurface biosensor based on quasi-bound states in the continuum for human serum albumin detection

Year: 2025

Type: article

Abstract: Accurate and sensitive detection of trace-level biomarkers is of vital importance for early disease diagnosis and timely intervention. In this work, we theoretically and experimentally present a metasurface biosensor based on quasi-bound states in the continuum ( q -BIC) with a high Q -factor for ultrasensitive detection of human serum albumin (HSA). Rigorous multipole decomposition and near-field distribution analysis reveal that the q -BIC resonance is dominated by the magnetic dipole (MD) mode. The strong near-field enhancement generated by this q -BIC resonance significantly enhances the light-analyte interaction, enabling the excellent sensing performance with a simulated refractive index sensitivity of 510 nm/RIU and a simulated FOM of 1637 RIU -1 for the proposed metasurface. The further experiment demonstrates that the limit of detection (LOD) for HSA reaches 2.3 ng/mL. This metasurface biosensor is highly sensitive, label-free, and cost-effective, showing great potential for practical biomedical detection.

Source: Optics Express

DOI: 10.1364/oe.578467

Authors: Xuan Zhang, Lijun Wei, Siqi Zhu, Zhenqiang Chen

Language: English

Topic: Metamaterials and Metasurfaces Applications

Subfield: Electronic, Optical and Magnetic Materials

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,270

Funders: National Natural Science Foundation of China, Fundamental Research Funds for the Central Universities, Key Technologies Research and Development Program of Guangzhou

Awards: G4353570351, G649618261, G8629168264