A PEGDA hydrogel nanocomposite to improve gold nanoparticles stability for novel plasmonic sensing platforms

Abstract

A 3D plasmonic sensing platform that combines the properties of citrate gold nanoparticles (AuNPs) and poly-(ethylene glycol) diacrylate (PEGDA) hydrogels is proposed as a nanocomposite hybrid material for biosensing applications, whose optical properties and sensitivity can be tuned by varying the particle mean diameter as also predicted by the Mie theory. It is found that AuNPs embedded in the hydrogel network are more stable when compared to the colloidal aqueous solutions. PEGDA hydrogel physically retains the gold nanoparticles even after a full swelling process during immersion in liquids. Such a property is confirmed by exposing the AuNPs-containing PEGDA hydrogels to organic solvents and buffers that would usually cause the aggregation of the nanoparticles in solution. Moreover, biotin, as a small molecule model, has been captured, and optically detected with a transmission mode customized setup, by a cysteamine modified AuNPs-containing PEGDA hydrogel layer to achieve a biorecognition hybrid device.

SERS Quantification of Galunisertib Delivery in Colorectal Cancer Cells by Plasmonic‐Assisted Diatomite Nanoparticles

“…Conversely, the gelatin capping in the DNP-AuNPs-LY@Gel complex caused a 10 nm red-shift of the LSPR due to the increase of the effective refractive index in the NP surroundings. [36] Figure 1e shows the FTIR spectra of the DNPs (black curve), DNPs-AuNPs (red curve), and DNPs-AuNPs-LY@Gel (green curve) suspension. FTIR spectra of samples were characterized by two peaks at 1100 and 800 cm −1 related to the asymmetric and symmetric stretching modes of siloxane (Si-O-Si), respectively; [37] the features at 3400 and 1640 cm −1 were due to the O-H stretching and O-H bending of water physically absorbed on the silica surface.…”

Thermoplasmonics with Gold Nanoparticles: A New Weapon in Modern Optics and Biomedicine

“…A few research teams have investigated the possibility of developing smart plasmonic hydrogels for biomedical applications focusing their scientific activities on the use of different kind of polymer matrices, including chitosan‐based hydrogels, [ 81 ] polyvinyl alcohol (PVA), [ 82 ] DNA hydrogel, [ 83 ] and poly‐(ethylene glycol) diacrylate (PEGDA). [ 84 ] Although a broad range of hydrogels could be applied in this field incorporating AuNPs in their polymer networks, thermoresponsive polymers (e.g., PNIPAM) stand out from the crowd since, in this case, light could trigger a cascade‐like series of responses and new functionalities.…”

Recent Advances in the Fabrication and Functionalization of Flexible Optical Biosensors: Toward Smart Life-Sciences Applications

“…The proposed sensor was able to detect glucose concentrations down to a LOD of 10 pM, showing great potential as a cost-effective and highly sensitive platform for medical applications (Figure 3b). More recently, Miranda et al, proposed the design and a large-scale, low-cost fabrication strategy of a poly(ethylene) glycol diacrylate (PEGDA) hydrogel embedding size-varying citrate AuNPs [17,90]. They show how the hydrogel physically retains spherical AuNPs within the mesh network allowing increased stability of AuNPs.…”

“…The excitation of LSPs gives rise to a strong enhancement of the electromagnetic field in the surroundings of the nanoparticles, which makes their resonance locally sensitive to refractive index variations [15]. In particular, silver (Ag) and gold (Au) nanoparticles (NPs) have been studied deeply due to their capability of exhibiting LSPs in the visible region of the spectrum, thus allowing the design of refractive index [16,17] and colorimetric [18][19][20] optical biosensors. When a target analyte is recognized by the nanoparticles, a resonance shift, proportional to the concentration of the analyte, can be measured through UV-vis spectroscopy.…”

“…(c) PEGDA hydrogel nanocomposite embedding AuNPs: Schematics of the functionalization procedure involving citrate displacement with a cysteamine modification of AuNPs and the subsequent sulfo-NHS biotin grafting on the available amino groups of cysteamine within the nanocomposite, and LSPR λ max (black squares) as a function of the biotin concentration (from 25 µM to 10 mM). Adapted from[17] Copyright (2021), with permission from AIP Publishing.…”