Mass fabrication of hierarchical nanostructures based on plasmonic nanochemistry for ultra-sensitive optical sensing

Abstract

We show a facile and inexpensive way, termed as plasmonics induced surface modification (PISM), to modify large-scale plasmonic nanostructures by growing Ag nanoislands (NIs) onto their surface merely by simple LED-irradiation. Both the size and density of the Ag NIs can be well regulated by adjusting the irradiating duration. The NIs modification in this system is ascribed to the photocatalytic effect resulting from the enhanced electric fields (E-field) of the plasmonic substrates. The obtained large-scale hierarchical Ag NIs-modified substrates with dense hotspots serve as high-performance surface enhanced Raman scattering (SERS) substrates with the limit of detection to be 10−17 M. Moreover, the structural advantages of the original substrates can be retained and developed. An effective wearable SERS device of glucose detection is further demonstrated. Overall, PISM is promising to be a universal surface modification methodology to expand the variety and complexity of nanostructures, and will be an effective complement to the existing research of plasmonic nanochemistry.