Overview

• The biosensor relies on inelastic electron tunneling to produce and detect light simultaneously without external illumination sources.
• A gold metasurface of nanoscale wires serves as both the tunneling barrier and a nanoantenna array to concentrate emitted photons for molecular sensing.
• Laboratory tests showed the device can detect amino acids and polymers at picogram concentrations, matching the sensitivity of leading label-free biosensors.
• The fully integrated sensor combines on-chip light generation and detection within an active area smaller than one square millimeter.
• Published in Nature Photonics, the compact platform is compatible with standard manufacturing techniques, positioning it for future handheld diagnostics and real-time environmental monitoring.