Molecularly linked 3D plasmonic nanoparticle core/satellite assemblies: SERS nanotags with single-particle Raman sensitivity

Abstract

A fast, generic, and suspension-based route to highly SERS-active assemblies of noble metal nanoparticles (Au, Ag) with small core-satellite gaps and single-particle Raman sensitivity is presented. Rationally designed, heterobifunctional Raman reporters serve as molecular linkers for electrostatic conjugation of the small satellites to the large core.

Rapid, Quantitative, and Ultrasensitive Point‐of‐Care Testing: A Portable SERS Reader for Lateral Flow Assays in Clinical Chemistry

“…2 nm) between the satellites and the core for strong plasmonic coupling and thereby large field enhancements for generating strong SERS signals from the Raman reporter thio-2-naphthol (TN). [7] The EM images of a single approximately 85 nm large Au/ Au core/satellite particle in Figure 2 a show that the satellites were relatively evenly distributed over the surface of the core. Correlative Rayleigh/SERS single particle (SP) imaging [8] demonstrates that the majority of the Au/Au core/satellite particles is SERS-active at the SP level (Figure 2 b), which clearly demonstrates the high SERS brightness of the nanotags.…”

Localization of PD‐L1 on single cancer cells by iSERS microscopy with Au/Au core/satellite nanoparticles

“…However, instead of labeling the antibody with an enzyme or a fluorophore, a molecularly functionalized noble metallic nanoparticle is employed . In our work we used Au/Au core/satellite particles with Raman‐active reporter molecules on the surface . The unique Raman signature of the molecule can be enhanced by the gold nanostructure upon resonant optical excitation and is used for the identification of the particles .…”

Modular assembly of plasmonic core–satellite structures as highly brilliant SERS-encoded nanoparticles

“…15,16 Core-satellite structures are typically produced via wet chemical methods where the nanoparticle assembly is chemically mediated by either (i) complementary ligands with selective recognition capabilities such as DNA, antibodies/antigens, etc., [17][18][19][20][21][22] or (ii) molecular linkers that directly bridge the plasmonic units via covalent or electrostatic interactions of their functional groups (usually located at opposite ends of the molecular structure). [23][24][25][26][27][28] However, the intrinsic DNA length required to ensure stable hybridization precludes the possibility of tuning the interparticle separation at short distances, which results in rather moderate enhancing capabilities. 29 Similar limitations are encountered with the use of other bulky macromolecules, such as proteins, 25 or branched polymers.…”