Rapid high-sensitivity WS-SPRI via programmable LED binary encoding and Hilbert–Huang transform

We present a wavelength-scanning surface plasmon resonance imaging platform integrating three synergistic innovations: a programmable narrowband LED array, binary-encoded spectral multiplexing, and Hilbert–Huang transform-based computational phase extraction. The LED illumination eliminates speckle noise and spectral broadening, while binary multiplexing compresses each spectral cycle to six measurements, achieving 0.3 s/frame temporal resolution. The Hilbert–Huang transform retrieves a Hilbert-derived computational phase directly from reconstructed reflectance spectra without physical interferometric modulators, enabling a refractive-index resolution of 5.94 × 10−7 RIU. High-throughput parallel kinetic analysis of antigen–antibody interactions yields a detection limit of 8.67 ng/ml. This work establishes an accessible, high-performance SPRI platform for quantitative label-free biosensing.