Molecularly defined plasmonic engineering to visualize antibody binding events by eye

摘要

We report a novel plasmonic tuning technique which allows colorimetric, naked-eye detection of protein-protein binding at extreme sensitivities. Utilizing an engineered approach to molecularly-driven plasmonic-coupling, we construct three-part plasmonic "bowtie" structures within protein nanoarrays using single biomolecular binding events. Precise molecular positioning of single gold nanaoparticles inside plasmonic bowties allows us to shape the plasmon supported by each array element in order to engineer a visible color-shift. By ensuring that only a single binding site is available inside each feature, we ensure plasmon homogeneity across the array, a unique technological solution which is essential to providing the sensitivity and observability we demonstrate here. This work represents a step-change in molecularly-mediated plasmonics and colorimetric biosensing, enabling biologically-controlled nanoengineering at single-protein resolutions. The potential applications of this powerful technique are not limited to biosensing and point-of-care diagnostics, and will also impact the emerging fields of molecularly driven nanoengineering and electronics.