Surface Plasmon Resonance Imaging for Multidimensional Seed Vigor Phenotyping: From Single-Analyte Detection to...

Global food security faces escalating pressures from climate change, population growth, and resource limitations. Seed vigor, a complex physiological trait governing germination potential and stress resilience, remains critically underserved by conventional testing protocols that are destructive, time-intensive, and incompatible with industrial throughput. Surface plasmon resonance imaging (SPRi) offers a distinctive biosensing paradigm characterized by label-free detection, real-time kinetic analysis, and massively parallel multiplexing. Yet the agricultural SPR literature has been shaped by a single-analyte paradigm optimized for pesticide and pathogen detection, a framework that proves insufficient for the integrated interpretation of multiple biomarker panels that seed vigor demands. The biomarker panels considered here span macromolecular effectors that fall squarely within the direct detection range of SPRi and small-molecule osmoprotectants that are accessible through competitive, aptamer-based, or molecularly imprinted formats, a mixed-format multiplexing strategy for which experimental precedents on single sensor arrays exist. This review critically examines the operational boundaries of SPR/SPRi in agricultural matrices, surveys demonstrated performance across residue detection, soil monitoring, and breeding applications, and identifies why these achievements do not constitute a sufficient foundation for seed vigor assessment. We then analyze how SPRi technology must be strategically redesigned for non-destructive seed vigor evaluation, addressing biomarker selection criteria, non-invasive sampling hierarchies, surface functionalization for complex seed exudates, and kinetic phenotyping architectures for batch screening and stress-response fingerprinting. Performance enhancement through nanomaterial amplification, machine learning-based data interpretation, and microfluidic integration is evaluated alongside persistent gaps in matrix validation, biomarker standardization, and inter-laboratory reproducibility. The strategic significance of SPRi-enabled seed quality assurance for sustainable global agriculture is discussed in the context of these translational challenges.