Chip-Based Metasurface Detects Traumatic Brain Injury Biomarkers at Femtogram Levels

The lab study shows an ultrasensitive optical chip that reads tiny biomarker bindings by shifts in a narrow light-reflection dip and signals a path toward point-of-care tests.

Overview

Researchers published the work in Optical Materials Express and publicized it on June 23–24, 2026, reporting a lab demonstration of a new metasurface biosensor.
The device uses a high-Q corrugated gold surface coated with specific antibodies so that when target proteins bind the local refractive index changes and a narrow reflection-spectrum dip shifts in wavelength.
In controlled tests the team measured GFAP and S100β across 1 fg/mL to 100 ng/mL and reported sub-femtogram-per-milliliter sensitivity with clear, concentration-dependent wavelength shifts.
The sensor showed strong discrimination versus non-target controls but remains preclinical because fabrication is currently expensive and the system needs packaged fluid handling and validation with complex clinical samples and patient cohorts.
If engineering and clinical steps succeed the platform could enable rapid, finger-prick or ambulance-based triage that speeds diagnosis and may reduce unnecessary CT scans by identifying low‑risk and higher‑risk TBI cases earlier.