Designing Gold Nanoparticle-Ensembles as Surface Enhanced Raman Scattering Tags inside Human Retinal Cells

Abstract

Apart from the traditional development of surface-enhanced raman scattering (SERS) substrates for ultrasensitive spectroscopic analysis, an increasing interest is given nowadays to the design of the so-called SERS nanotags which integrate multiple SERS applications into single plasmonic nanoparticles. The fabrication of SERS tags is still a challenging task due to the complicated fabrication process. Typically, SERS tags are hybrid nanoconstructs consisting in a unique plasmonic nanoobject encoded with specific reporter molecules and enveloped in a protective shell that provides both biocompatibility and targeting function. Herein, we produce effective SERS tags consisting in small aggregates of gold nanoparticles (mainly dimers and trimers) which are captured from solution and then transferred into cells to perform as individual plasmonic nanostructures. Actually the small aggregates formed under controlled conditions are stabilized in solution by interlocking into a polymeric envelope made of thiol-modified poly(ethylene) glycol (PEG-SH). No further encoding operation is necessary in our case since part of ascorbic acid used as reducing agent remains attached in the interparticle junctions, providing persistent and strong SERS signal when the fabricated tags are internalized by human retinal cells. Our studies demonstrate a promising potential of new SERS-active nanoparticles to serve as effective reporters for biomedical tracing and imaging.

Effect of Reaction Temperature on Shape Evolution of Palladium Nanoparticles and Their Cytotoxicity against A-549 Lung Cancer Cells

“…29 The bands at 1076, 1170, and 1516 cm –1 are because of (C–O–H bend), CH 2 rocking, and CH 2 scissoring. 30…”

The Collagen-Based Medical Device MD-Tissue Acts as a Mechanical Scaffold Influencing Morpho-Functional Properties of Cultured Human Tenocytes

“…The Raman analysis was focused on these two regions (Figure 4d,e). The crystal part presents the typical sharp peaks of crystal structures, with peaks attributable to the characteristic signals of riboflavin (750, 1345, 1410 cm −1 ) and ascorbic acid (605 and 632 cm −1 ) (Figure 4d), both present in the MD product [25,26]. The fibrillary part was mainly composed of collagen due to the presence of characteristic peaks at 536, 858, 919, 1065, 1343, 1454 and 1674 cm −1 (Figure 4e) [27].…”

Antioxidant‐modulated cytotoxicity of silver nanoparticles

“…In order to characterize the AgNPs more precisely, the chemical composition of their stabilizing layers was assessed using SERS. In Figure 2, the SERS spectra of the suspensions of AAgNPs and GAAgNPs, recorded at a concentration of 60 mg L −1 and an ionic strength of 0.1‐M NaCl, were compared with the Raman spectra of AA and GA. For the sake of convenience, the recorded bands and proposed band assignments, developed on the basis of data from the literature (Alvarez‐Ros et al, 2001; Boca et al, 2012; Garrido et al, 2016 ; Panicker et al, 2006), have been collected in Table S1.…”