Visible-Light Driven Implantable Nanophotonic Biosensor for Continuous Glucose Monitoring via Metalloporphyrin Q-Band Modulation and Enzymatic Cascade Stabilization

Continuous glucose monitoring (CGM) is essential for diabetes management. Optical CGM provides a promising approach, yet current existing optical platforms face challenges including phototoxic excitation, shallow tissue penetration, and limited hardware compatibility. Here, we report a visible-light activated implantable nanophotonic biosensor that enables long-term in vivo glucose tracking through dual spectral and biochemical engineering. The sensor leverages Q-band of metalloporphyrins, shifting excitation from the phototoxic near-UV/blue B-band to the safer visible-light region, and couples with a rhodamine via Förster resonance energy transfer (FRET) to achieve efficient photon harvesting, ratiometric calibration, and CMOS-compatible optical readout. To stabilize enzymatic performance and mitigate oxidative damage, a glucose oxidase/catalase (GOx/CAT) cascade rapidly decomposes hydrogen peroxide (H₂O₂) byproducts, preserving sensitivity during extended implantation. This integrated design yields a biocompatible, optically compatible, and long-term stable nanophotonic sensing platform, advancing the development of smart terminal-integrated CGM systems with robust in vivo performance and strong translational potential for personalized diabetes management.