title: Gold Superparticles Functionalized with Azobenzene Derivatives: SERS Nanotags with Strong Signals.
abstract: The surface-enhanced Raman spectroscopy (SERS) nanotag was proposed as a substitute for fluorescent dye for imaging and biosensors several decades ago. However, its weak signal and poor reproducibility has hindered its application. Here, we report a new strategy to form Au superparticles (AuSPs) with high SERS enhancement via one-pot formation and self-assembly of Au nanoparticles (NPs). An azobenzene-carrying Raman reporter was synthesized to exhibit a large Raman cross-section and multiple bands. The self-assembly of the Raman reporter on AuSPs generated SERS nanotags with intense signals. A Raman reporter carrying boronic acid and azobenzene groups displayed six distinctive bands. Its corresponding SERS nanotag demonstrated a high sensing ability toward glycoprotein through aggregation-induced SERS enhancement or as a substitute for labeled antibodies in an immunoassay of the glycoprotein.
authors.affiliation: Department of Biomedical Engineering, National University of Singapore , 4 Engineering Drive 3, Engineering Block 4, Singapore 117583, Singapore.
authors.forename: Ying
authors.identifier: http://orcid.org/0000-0003-2204-0663
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Department of Biomedical Engineering, National University of Singapore , 4 Engineering Drive 3, Engineering Block 4, Singapore 117583, Singapore.
authors.forename: Kittithat
authors.initials: K
authors.lastname: Promthaveepong
authors.affiliation: Division of Bioengineering, School of Chemical & Biomedical Engineering, Nanyang Technological University , 70 Nanyang Drive, Singapore 637457, Singapore.
authors.forename: Nan
authors.initials: N
authors.lastname: Li
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D006046:Gold; D053768:Metal Nanoparticles; D015203:Reproducibility of Results; D013059:Spectrum Analysis, Raman
chemical_list: D001391:Azo Compounds; D006046:Gold; C009850:azobenzene
keywords: SERS nanotag; azobenzene; gold superparticles; sensor