We conceive, design, experimentally demonstrate, and validate high‑Q all‑dielectric metasurfaces and other resonant nanophotonic devices to enhance light–matter interaction for label‑free sensing and functional imaging. Work spans quasi‑BIC modes, spectral engineering, and field localization, with CMOS‑compatible micro/nanofabrication, optoelectronic instrumentation for signal acquisition/processing, and systematic testing for performance, reliability, and scalability.