Halloysite Nanotubes with Immobilized Plasmonic Nanoparticles for Biophotonic Applications

Abstract

Halloysite nanotubes (HNTs) with immobilized gold (Au) and silver (Ag) nanoparticles (NPs) belong to a class of nanocomposite materials whose physical properties and applications depend on the geometry of arrangements of the plasmonic nanoparticles on HNT’ surfaces. We explore HNTs:(Au, Ag)-NPs as potential nano-templates for surface-enhanced Raman scattering (SERS). The structure and plasmonic properties of nanocomposites based on HNTs and Au- and Ag-NPs are studied by means of the transmission electron microscopy and optical spectroscopy. The optical extinction spectra of aqueous suspensions of HNTs:(Au, Ag)-NPs and spatial distributions of the electric fields are simulated, and the simulation results demonstrate the corresponding localized plasmonic resonances and numerous “hot spots” of the electric field nearby those NPs. In vitro experiments reveal an enhancement of the protein SERS in fibroblast cells with added HNTs:Ag-NPs. The observed optical properties and SERS activity of the nanocomposites based on HNTs and plasmonic NPs are promising for their applications in biosensorics and biophotonics.

Prokaryotic and eukaryotic toxicity of halloysite decorated with photoactive nanoparticles

“…Investigation of antibacterial properties of plasmonic materials has not been extensively studied, hence there are a lot of works dedicated to the synthesis and investigation of plasmonic nanomaterials based on halloysite clay tubes. [57][58][59] Photocatalytic properties of clay nanotube based composites have also been investigated in recent years. Activity of clay tube based composites is highly related to the interaction of clay with bacteria, today the mechanism of the interaction of bacteria with clay tubes is not exhaustively described.…”

“…58,65 Adsorption on clay tubes makes it possible to regulate the distance between particles and tune plasmonic field intensity. 59 Recently, Au NPs were stabilized on the surface of aminosilane modified halloysite. 66 This material was studied as a potential hyperthermia material.…”

“…58,65 Adsorption on clay tubes makes it possible to regulate the distance between particles and tune plasmonic field intensity. 59…”

Surface-Enhanced Raman Scattering from Dye Molecules in Silicon Nanowire Structures Decorated by Gold Nanoparticles

“…Now, the most prominent SERS-active substrates employ an effect of the enhanced electric field due to localized surface plasmon resonance (LSPR) in what are called plasmonic metal nanoparticles (NPs) [ 3 , 4 ]. Silver (Ag) and gold (Au) NPs with amazing plasmonic characteristics are usually used to detect low concentrations of biomolecules by SERS [ 13 , 14 , 15 , 16 , 17 ]. While the SERS signal promoted by individual plasmonic NPs is characterized by relatively low intensity and poor reproducibility, which become a major obstacle for practical application and commercialization, the use of specifically designed nanostructured substrates as templates for plasmonic NPs is the main direction for the development of SERS sensing systems for different biomolecules [ 16 ], living cells [ 17 ], and biosystems [ 18 , 19 , 20 ].…”

“…The performance of SERS-active surfaces is usually characterized by an enhancement factor, which depends on the substrate morphology and physical properties of plasmonic NPs [ 2 , 3 ]. Maximal SERS efficiency is often associated with the formation of a so-called “hot spot” of the electric field related to plasmonic NPs [ 3 , 17 , 18 ]. The reproducibility and stability of the SERS signal is an important metric for evaluating the effectiveness of SERS-active surfaces, which means that the surface must be well controllable and stable for a long time [ 45 , 46 , 47 ].…”