Al-Shammari, Rusul M.Rusul M.Al-ShammariAl-Attar, NebrasNebrasAl-AttarManzo, MicheleMicheleManzoGallo, KatiaKatiaGalloRodriguez, Brian J.Brian J.RodriguezRice, James H.James H.Rice2021-03-022021-03-022018 Ameri2018-03-15ACS Omega2470-1343http://hdl.handle.net/10197/12002Single-molecule detection by surface-enhanced Raman scattering (SERS) is a powerful spectroscopic technique that is of interest for the sensor development field. An important aspect of optimizing the materials used in SERS-based sensors is the ability to have a high density of "hot spots" that enhance the SERS sensitivity to the single-molecule level. Photodeposition of gold (Au) nanoparticles through electric-field-directed self-assembly on a periodically proton-exchanged lithium niobate (PPELN) substrate provides conditions to form well-ordered microscale features consisting of closely packed Au nanoparticles. The resulting Au nanoparticle microstructure arrays (microarrays) are plasmon-active and support nonresonant single-molecule SERS at ultralow concentrations (<10-9-10-13 M) with excitation power densities <1 × 10-3 W cm-2 using wide-field imaging. The microarrays offer excellent SERS reproducibility, with an intensity variation of <7.5% across the substrate. As most biomarkers and molecules do not support resonance enhancement, this work demonstrates that PPELN is a suitable template for high-sensitivity, nonresonant sensing applications.Electronic-eCollectionenThis document is the Accepted Manuscript version of a Published Work that appeared in final form in Langmuir, copyright © 2018 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs10.1021/acsomega.7b01285.Power-law analysisLithium-niobateSurface-enhanced Raman scatteringPolarizationJournal Article333165317210.1021/acsomega.7b012852020-12-0912/IP/155607/IN.1/B931https://creativecommons.org/licenses/by-nc-nd/3.0/ie/