Multilayer Nanoparticles Research Articles

An efficient co-delivery system based on multilayer structural nanoparticles for programmed sequential release of resveratrol and vitamin D3 to combat dextran sodium sulfate-induced colitis in mice

Multilayer structural nanoparticles (MSNPs) fabricated by layer-by-layer self-assembly were used for the co-encapsulation of resveratrol (Res) and vitamin D3 (Vd). Res and Vd co-encapsulated MSNPs (Res-Vd-MSNPs) were evaluated by appearance, morphology, particle size, ζ potential and encapsulation efficiency (EE). The results showed that Res-Vd-MSNPs were spherical in shape with a particle size of 625.4 nm and a surface charge of +26.1 mV. The EE of Res and Vd was as high as 93.6 % and 90.8 %, respectively. Res-Vd-MSNPs exhibited better stability and lower degradation rate in simulated gastric fluid, allowing the programmed sequential release of Vd and Res in simulated intestinal fluid and simulated colonic fluid, which was also confirmed by in vivo fluorescence imaging of mice. In addition, Res-Vd-MSNPs effectively alleviated the clinical symptoms of dextran sulfate sodium salt (DSS)-induced colitis in mice, including weight loss, diarrhea and fecal bleeding, and it especially exerted a preventive effect on DSS-induced colon tissue damage and colon shortening. Furthermore, Res-Vd-MSNPs suppressed the expression of anti-inflammatory cytokines such as TNF-α, IL-1β and IL-6 and ameliorated DSS-induced oxidative damage, decreased colonic myeloperoxidase (MPO) and nitric oxide (NO) activities and elevated glutathione (GSH) level in DSS-treated mice. This study illustrated that MSNPs were potential carriers for developing the co-delivery system for the synergistic prevention and treatment of ulcerative colitis.

ASSESSMENT OF ACUTE NEUROTOXICITY OF NITROGEN-DOPED MULTILAYER GRAPHENE NANOPARTICLES AND THEIR CAPABILITY TO CHANGE Cd2+/Pb2+/Hg2+-INDUCED INJURY IN BRAIN CORTEX NERVE TERMINALS

Graphene materials are widely used in different technologies and certainly released into aquatic and air surroundings being environmental pollution components. Nitrogen‑doped graphene nanomaterials have great potential for application, in particular, in energy storage, as electrochemical sensors and waste water treatment. Aim. Evaluate neurotoxic risk of nitrogen-doped multilayer graphene. Methods. Here, nitrogen-doped multilayer graphene nanoparticles (N-MLG) were synthesized by means of electrochemical exfoliation of high-purity graphite rods in NaN3-based electrolyte and characterised using TEM, AFM and UV-vis spectroscopy. Neuroactive features of N-MLG were assessed in isolated cortex nerve terminals (synaptosomes) analysing the extracellular level of excitatory neurotransmitter L-[14C] glutamate and inhibitory one [3H]GABA. Results. It was revealed that N-MLG did not affect the extracellular synaptosomal levels of L-[14C] glutamate and [3H]GABA within the concentration range 0.01–0.5 mg/ml, and an increase in a concentration up to 1 mg/ml caused an insignificant increase (tendency to increase) in these levels for both neurotransmitters. To analyse a capability of interaction with heavy metals in biological system, N-MLG was investigated using model of acute Cd2+/Pb2+/Hg2+-induced neurotoxicity in nerve terminals. In was revealed that Cd2+/Pb2+/Hg2+-induced increase in the extracellular level of L-[14C] glutamate and [3H]GABA was not changed by N-MLG. Conclusions. N-MLG does not possess neurotoxic signs and is biocompatible within the concentration range 0.01–1 mg/ml. In biological system, N-MLG did not mitigate/aggravate Cd2+/Pb2+/Hg2+-induced neurotoxicity in nerve terminals.

Simultaneous Imaging of Multiple miRNAs in Mitochondria Controlled by Fluorescently Encoded Upconversion Optical Switches for Drug Resistance Studies.

Mitochondrial miRNAs (mitomiRs) are essential regulators of biological processes by influencing mitochondrial gene expression and function. To comprehensively understand related pathological processes and treatments, simultaneous imaging of multiple mitomiRs is crucial. In this study, we present a technique that enables simultaneous monitoring of multiple mitomiRs in living cells using a near-infrared (NIR) photoactivated controlled detection probe (PD-mFleU) with a fluorescence-encoded error correction module and a nonsupervised machine learning data-processing algorithm. This method allows controlled sensing imaging of mitomiRs with a DNA reporter probe that can be activated by NIR light after targeted mitochondrial localization. Multilayer upconversion nanoparticles (UCNPs) are used for encoding probes and error correction. Additionally, the density-based spatial clustering of applications with the noise (DBSCAN) algorithm is used to process and analyze the image. Using this technique, we achieved rapid in situ imaging of the abnormal expression of three mitomiRs (miR-149, miR-590, and miR-671) related to mt-ND1 in drug-resistant cells. Furthermore, upregulating the three mitomiRs simultaneously efficiently reverted drug-resistant cells to sensitive cells. Our study provides an analytical strategy for multiplex imaging of mitomiRs in living cells with potential clinical applications.

Gold nanoparticles engineered nanoporous membrane with sandwich structure for sensitive electrochemical quantification of exosome

Exosome has been identified as an excellent potential biomarker for tumor diagnosis. Herein, electrochemical aptasensor for exosome detection was developed via a sandwich-structured nanoporous membrane which was fabricated by assembling multilayer gold nanoparticles (mulAu) and monolayer gold nanoparticles (monAu) on the opposite side of a nanoporous alumina membrane (NAM). The tumor-derived exosomes can be efficiently captured by the specific probes confined on the monAu side of the membrane. And the mulAu side that was tightly attached with a Si wafer allowed the electrochemical exosome detection by monitoring the amperometric signal of ferricyanide that transported across the nanochannel array of the membrane. After optimization of pore diameter of the NAM, base sequence of the capture probe and incubation temperature as well as incubation time for exosomes, this NAM-based electrochemical aptasensor was applied to the quantification of the MCF-7 cells-derived exosomes. The steady state current displayed linearity relationship with the concentration of the exosomes in a broad range of 103 to 107 particles μL−1, along with a detection limit of 2.8 × 102 particles μL−1. By changing capture probe, this sandwich-structured membrane could be further extended to label-free, sensitive and rapid quantification of other tumor-associated vesicles.

Progressive algorithm for the scattering of electromagnetic waves by a multilayered eccentric sphere.

This paper presents a general progressive algorithm for the computational study of electromagnetic wave scattering by a multilayered eccentric nanoparticle. The presented methodology is based on a combination of the vector addition theorem for spherical wave functions and an efficient progressive algorithm that matches the boundary conditions of every two adjacent shell layers from the outmost to the innermost layer. As a result, only a solution of small-sized matrices is required rather than solving a large set of system equations as reported in other works. With the developed approach, explicit expressions of the Mie scattering coefficients of the eccentric particle can be obtained. Moreover, the Mie coefficients of a specific inner layer could be calculated selectively, instead of having to compute those of all layers of the entire particle as required by other algorithms. The presented methodology can be used to study practically any type of spherical particle inclusions and the most widely studied cases such as scattering by solid particles, concentric particles, and inclusions with centers displaced along a straight line are just special cases of the algorithm presented. Computed results are also presented, illustrating that the eccentric structure allows extra freedom in the design of multilayered nanoparticles for optical applications.

Alanine aminotransferase detection using TIT assisted four tapered fiber structure-based LSPR sensor: From healthcare to marine life

Alanine aminotransferase (ALT), a type of inactive enzyme largely present in fish liver cells, is essential for the tricarboxylic acid (TCA) cycle. Monitoring ALT activity in the blood/hepatocellular layer has been demonstrated to be a sensitive sign of liver dysfunction and an essential method for determining the health status of fish. This study details the development of a multi-layer material (hybrids of graphene oxide and multi-walled carbon nanotubes (GO/MWCNTs), gold nanoparticles (AuNPs), and glutamate oxidase (GluOx) enzyme) immobilized localized surface plasmon resonance based unique fiber structure biosensor for the quantitative determination of ALT biomolecules at concentrations ranging from 0 to 1000 U/L. For this kind of detection, a novel taper-in-taper with four tapered (TIT4T) structure based on single-mode fiber has been developed. In addition to AuNPs, GO/MWCNTs were immobilized in the probe's sensing region to increase its LSPR efficiency and sensitivity. Synthesis of AuNPs was carried out utilizing the Turkevich method. The selectivity of the sensor is ensured by the effective immobilization of GluOx on the surface treatment. The linearity of sensor is in the range of 0–1000 U/L, whereas the sensitivity, limit of detection, and detection time are individually found at 7.5 p.m./(U/L), 4.84 U/L and 20 min, respectively. After evaluating the prospective applications of the sensors, the sensors' reusability, reproducibility, stability, pH test, and selectivity have all been found to be satisfactory. Proposed fiber optic biosensors have high sensitivity, robustness, reliability, fast detection, no electromagnetic interference, low cost, real-time monitoring, and biocompatible.

Multifunctional core-shell nanoparticles for temperature sensing and anti-counterfeiting

In this paper, the multi-functional multi-layer core-shell structure NaYF4: Ce3+/Eu3+@NaYF4 @NaYF4: Ho3+/Yb3+ nanoparticles (NPs) were prepared. These multi-layer NPs can be applied in temperature sensing with high relative sensitivity. Moreover, these NPs can be used in multimode optical anti-counterfeiting. Based on structure design and doped earth ions optimized, the maximum relative sensitivity is further promoted from 0.9 %·K−1 at 234 K (Eu/Ho) to 5.1 %·K−1 at 113 K (Ce/Eu@Y@Ho/Yb) by the blocking effect of the inter layer and by cross-relaxation of introducing Ce3+ and Yb3+ ions. Meanwhile, by introducing Ce3+ and Yb3+ ions, the NPs provide multimode emissions under multiple excitations, which are beneficial for the application of optical anti-counterfeiting. The NPs present increased sensitivity of temperature sensing and improved security of optical anti-counterfeiting, which has promising applications in biological cell calibration, micro-integrated circuits, etc.

Seed-assisted electrodeposition of multilayer Au nanoparticles-assembled films for sensitive surface-enhanced Raman scattering detection

Surface-enhanced Raman scattering (SERS) spectroscopy can be used to realize sensitive rapid detection of molecules. Three-dimensional (3D) SERS substrates can provide more hotspots within the excitation laser beam when compared with the corresponding two-dimensional (2D) SERS substrates. Most of the methods for fabrication of 3D SERS substrates involve complex processes. Therefore, it is significant to develop a simple and effective method for fabrication of 3D SERS substrates. Here, a seed-assisted electrodeposition approach is developed for fabrication of a 3D SERS substrate composed of multilayer Au nanoparticles. Interestingly, it is demonstrated that a uniform film composed of multilayer Au nanoparticles that can serve as a 3D SERS substrate can be achieved directly by one-step electrodeposition on a conductive surface coated with monolayer Au seeds. It is found that a diffusion-controlled growth during electrodeposition narrows the nanoparticle size distribution and results monosized Au nanoparticles. The as-prepared multilayer Au nanoparticles-assembled film shows high SERS sensitivity and good spectral uniformity. For SERS detection of rhodamine 6G, a limit of detection as low as 3.4×10−12 M has been achieved. Moreover, good spectral uniformity (relative standard deviation ∼7.8%) and high substrate-to-substrate reproducibility (relative standard deviation ∼8.6%) have also been demonstrated. The as-prepared multilayer Au nanoparticles-assembled film is used to detect organic pollutants such as dye molecule crystal violet (CV) and methylene blue (MB). Calibration curves with a linear correlation between the logarithmic SERS intensity and logarithmic concentration of CV and MB have been obtained. Limit of detections for CV and MB are 1.2×10−8 M and 9.8×10−10 M, respectively. Therefore, the fabricated 3D SERS substrate has good application prospects in sensitive detection of organic molecules.

Exploring thermodynamic characteristics and magnetocaloric effect of an edge-decorated Ising multilayer nanoparticle with graphene-like structure

In this paper, the thermodynamic characteristics, magnetocaloric effect and ground-state properties of an edge-decorated Ising multilayer nanoparticle with graphene-like structure are studied by Monte Carlo simulation. The results reveal that size effect, crystal field, exchange coupling, and applied magnetic field can control the magnetic behaviors of the system. In addition, the curves of magnetic entropy change and relative cooling power (RCP) are given induced by various physical parameters.

Development, characterization and antimicrobial activity of multilayer silica nanoparticles with chlorhexidine incorporated into dental composites.

In this study a dentistry nanocomposite with prolonged antibacterial activity using silica nanoparticles (SNPs) loaded with chlorhexidine (CHX) was developed. SNPs were coated with the Layer-by-Layer technique. Dental composites were prepared with organic matrix of BisGMA/TEGDMA and SNPs with or without CHX (0, 10, 20 or 30% w/w). The physicochemical properties of the developed material were evaluated and agar diffusion method was used to test the antibacterial. In addition, the biofilm inhibitory activity of the composites was evaluated against S. mutans. SNPs were rounded with diameters about 50nm, the organic load increased with increasing deposited layers. Material samples with SNPs loaded with CHX (CHX-SNPs) showed the highest values of post-gel volumetric shrinkage, that ranged from 0.3% to 0.81%. Samples containing CHX-SNPs 30% w/w showed the highest values of flexural strength and modulus of elasticity. Only samples containing SNPs-CHX showed growth inhibition against S. mutans, S. mitis and S. gordonii in a concentration-dependent manner. The composites with CHX-SNPs reduced the biofilm formation of S. mutans biofilm at 24h and 72h. The nanoparticle studied acted as fillers and did not interfere with the evaluated physicochemical properties while providing antimicrobial activity against streptococci. Therefore, this initial study is a step forward to the synthesis of experimental composites with improved performance using CHX-SNPs.

Synthesis of non-planar graphene-wrapped copper nanoparticles with iron(III) oxide decoration for high performance supercapacitors

The performance of supercapacitors strongly depends on the electrochemical characterizations of electrode materials. Herein, a composite material consisted of iron(III) oxide (Fe2O3) and multilayer graphene-wrapped copper nanoparticles (Fe2O3/MLG-Cu NPs) is fabricated on a flexible carbon cloth (CC) substrate via two-step synthesis process for supercapacitor application. Where, MLG-Cu NPs are prepared on CC by one-step chemical vapor deposition synthesis approach; thereafter, the Fe2O3 is further deposited on the MLG-Cu NPs/CC via successive ionic layer adsorption and reaction method. The related material characterizations of Fe2O3/MLG-Cu NPs are well investigated by scanning electron microscopic, high resolution transmission electron microscopy), Raman spectrometer and X-ray photoelectron spectroscopy; the electrochemical behaviors of the pertinent electrodes are studied by cyclic voltammogram, galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy measurements. The flexible electrode with Fe2O3/MLG-Cu NPs composites exhibits the best specific capacitance of 1092.6 mF cm−2 at 1 A g−1, which is much higher than those of electrodes with Fe2O3 (863.7 mF cm−2), MLG-Cu NPs (257.4 mF cm−2), multilayer graphene hollow balls (MLGHBs, 14.4 mF cm−2) and Fe2O3/MLGHBs (287.2 mF cm−2). Fe2O3/MLG-Cu NPs electrode also exhibits an excellent GCD durability, and its capacitance remains 88% of its original value after 5000 cycles of the GCD process. Finally, a supercapacitor system consisted of four Fe2O3/MLG-Cu NPs/CC electrodes can efficiently power various light-emitting diodes (i.e. red, yellow, green, and blue lights), demonstrating the practical application of Fe2O3/MLG-Cu NPs/CC electrode.

Waterproof and ultrasensitive paper-based wearable strain/pressure sensor from carbon black/multilayer graphene/carboxymethyl cellulose composite

Huge electronic wastes motivated the flourishing of biodegradable electrically conductive cellulosic paper-based functional materials as flexible wearable devices. However, the relatively low sensitivity and unstable output in combination with poor wet strength under high moisture circumstances impeded the practical application. Herein, a superhydrophobic cellulosic paper with ultrahigh sensitivity was proposed by innovatively employing ionic sodium carboxymethyl cellulose (CMC) as bridge to reinforce the interfacial interaction between carbon black (CB) and multilayer graphene (MG) and SiO2 nanoparticles as superhydrophobic layer. The resultant paper-based (PB) sensor displayed excellent strain sensing behaviors, wide working range (−1.0 %–1.0 %), ultrahigh sensitivity (gauge factor, GF = 70.2), and satisfied durability (>10,000 cycles). Moreover, the superhydrophobic surface offered well waterproof and self-cleaning properties, even stable running data without encapsulation under extremely high moisture conditions. Impressively, when the fabricated PB sensor was applied for electronic-skin (E-skin), the signal capture of spatial strain of E-skin upon bodily motion was breezily achieved. Thus, our work not only provides a new pathway for reinforcing the interfacial interaction of electrically conductive carbonaceous materials, but also promises a category of unprecedentedly superhydrophobic cellulosic paper-based strain sensors with ultra-sensitivity in human-machine interfaces field.

Single-component multilayered self-assembling protein nanoparticles presenting glycan-trimmed uncleaved prefusion optimized envelope trimers as HIV-1 vaccine candidates

Uncleaved prefusion-optimized (UFO) design can stabilize diverse HIV-1 envelope glycoproteins (Envs). Single-component, self-assembling protein nanoparticles (1c-SApNP) can display 8 or 20 native-like Env trimers as vaccine candidates. We characterize the biophysical, structural, and antigenic properties of 1c-SApNPs that present the BG505 UFO trimer with wildtype and modified glycans. For 1c-SApNPs, glycan trimming improves recognition of the CD4 binding site without affecting broadly neutralizing antibodies (bNAbs) to major glycan epitopes. In mice, rabbits, and nonhuman primates, glycan trimming increases the frequency of vaccine responders (FVR) and steers antibody responses away from immunodominant glycan holes and glycan patches. The mechanism of vaccine-induced immunity is examined in mice. Compared with the UFO trimer, the multilayered E2p and I3-01v9 1c-SApNPs show 420 times longer retention in lymph node follicles, 20-32 times greater presentation on follicular dendritic cell dendrites, and up-to-4 times stronger germinal center reactions. These findings can inform future HIV-1 vaccine development.

Block Copolymer Enabled Synthesis and Assembly of Chiral Metal Oxide Nanoparticle

Chiral metal oxide nanostructures have received tremendous attention in nanotechnological applications owing to their intriguing chiroptical and magnetic properties. Current synthetic methods mostly rely on the use of amino acids or peptides as chiral inducers. Here, we report a general approach to fabricate chiral metal oxide nanostructures with tunable magneto-chiral effects, using block copolymer (BCP) inverse micelle and R/S-mandelic acid (MA). Diverse chiral metal oxide nanostructures are prepared by the selective incorporation of precursors within micellar cores followed by the oxidation process, exhibiting intense chiroptical properties with a g-factor up to 7.0 × 10-3 in the visible-NIR range for the Cr2O3 nanoparticle multilayer. The BCP inverse micelle is found to inhibit the racemization of MA, allowing MA to act as a chiral dopant that imparts chirality to nanostructures via hierarchical chirality transfer. Notably, for paramagnetic nanostructures, magneto-chiroptical modulation is realized by regulating the direction of the external magnetic field. This BCP-driven approach can be extended to the mass production of chiral nanostructures with tunable architectures and optical activities, which may provide insights into the development of chiroptical functional materials.

Region-specified inverse design of absorption and scattering in nanoparticles by using machine learning

Machine learning provides a promising platform for both forward modeling and the inverse design of photonic structures. Relying on a data-driven approach, machine learning is especially appealing for situations when it is not feasible to derive an analytical solution for a complex problem. There has been a great amount of recent interest in constructing machine learning models suitable for different electromagnetic problems. In this work, we adapt a region-specified design approach for the inverse design of multilayered nanoparticles. Given the high computational cost of dataset generation for electromagnetic problems, we specifically investigate the case of a small training dataset, enhanced via random region specification in an inverse convolutional neural network. The trained model is used to design nanoparticles with high absorption levels and different ratios of absorption over scattering. The central design wavelength is shifted across 350–700 nm without re-training. We discuss the implications of wavelength, particle size, and the training dataset size on the performance of the model. Our approach may find interesting applications in the design of multilayer nanoparticles for biological, chemical, and optical applications as well as the design of low-scattering absorbers and antennas.

Co-delivery system based on multilayer structural nanoparticles for programmed sequential release of fucoxanthin and curcumin

Multilayer structural nanoparticles (MSNPs) fabricated by gliadin (Gli), carboxymethyl konjac glucomannan (CMK) and chitosan hydrochloride (CHC) were used to co-encapsulate fucoxanthin (FUC) and curcumin (Cur), and the effect of CHC level on the physiochemical properties of MSNPs (FUC-Gli-CMK-Cur-CHC) was evaluated. The prepared FUC-Gli-CMK-Cur-CHC had a particle size of about 628.1 nm and showed a spherical shape with high ζ potential (+27.1 mV) and maximal encapsulation efficiency of FUC (96.3%) and Cur (72.8%). Lyophilized FUC-Gli-CMK-Cur-CHC exhibited excellent water redispersibility after the addition of CHC. Furthermore, the physical stability, storage stability and thermal stability of MSNPs were dramatically improved by CHC coating. FUC-Gli-CMK-Cur-CHC were shown to be effective at retarding the photo- and thermal-degradation of the encapsulated FUC and Cur. In addition, in vitro release and in vivo gastrointestinal distribution studies demonstrated that the prepared MSNPs exhibited programmed sequential release properties, which enabled the delivery of Cur and FUC in the small intestine and colon, respectively. This research provides new insights for MSNPs in constructing co-delivery systems and programmed sequential release of active substances.

Intensive study of coating multilayer TiO2 nanoparticles thin films used for optoelectronics devices

High-performance of TiO2 nanoparticles (NPs) thin films were synthesized using spin coating technique deposited on a glass substrate. The effect of the several layers of films which have formed is studied on the structure, morphology, surface, optical and electrical characteristics. From the analysis using X-ray diffractometry (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), raman spectroscopy, ultraviolet–visible spectrophotometer and impedance spectroscopy the obtained results show that anatase crystalline is obtained after annealing at 400 °C from TiO2 (NPs) in powder form. The surface of samples is uniform and the rms roughness is dependent on the number of layers and varied within the range 25.40–43.81 nm. The optical bandgap energy is obtained in the 2.9–3.2 eV range of multilayer TiO2 (NPs) thin films. The electrical characteristic analyzed as a function of temperature and frequency demonstrated a semiconducting behavior, and showed a decreased of resistance with the increase of temperature. The obtained activation energy based on impedance analysis is about 0.7 eV. It is showed that TiO2 deposited on the SnO2 glass substrate has anatase crystalline structure and their optical bandgap energy is about 3.0 eV. Electrical analysis shows semiconductor behavior over the explored temperature range from 400 °C.

Scattering of aggregated multi-layered biological cells by Bessel beams

Interactions between collective multi-layered cells and an off-axis high-order Bessel beam (HOBB) are investigated. The generalized Lorenz-Mie theory is applied to derive the expansion of HOBB. Based on the additional theorem, multiple scattering of collective multi-layered nanoparticles is obtained by considering the tangential continuous boundary conditions. The present theory and codes are proven to be effective by comparing with the simulations obtained from the computer simulation technology (CST) software. Numerical results concerning the effects of beam order, beam conical angle, spherical layer number, core radius and outer layer radius, outer layer refractive index and the spherical number on the scattering of various types of aggregated multi-layered particles are displayed in detail, which may provide critical support for analytically understanding the optical scattering characteristics of aggregated multi-layered biological cells of complex shapes and may find important applications in manipulating multi-layered biological structures.

A block elimination algorithm for multiple scattering of multilayered concentric nanoparticle aggregates

A block elimination algorithm for multiple scattering of multilayered concentric nanoparticle aggregates

Multifunctional Au@Ag@SiO2 Core–Shell–Shell Nanoparticles for Metal-Enhanced Fluorescence, Surface-Enhanced Raman Scattering, and Photocatalysis Applications

Au@Ag@SiO2 core-shell-shell nanoparticles (NPs) were prepared by a facile one-pot synthetic technique. The Au@Ag core size and SiO2 shell thicknesses are readily controlled by adjusting the precursor concentration. The multilayered NPs with dielectric SiO2 outer shells and bimetallic Au@Ag cores exhibited both the chemical stability of Au with the high scattering efficiency of Ag. Furthermore, the SiO2 shell is beneficial to the metal-enhanced fluorescence for biomedical applications. Metal-enhanced fluorescence, surface-enhanced Raman scattering, and photocatalytic activities of silica-coated Au@Ag, Ag, Au, and Au/Ag core-shell NPs were compared and discussed. The size and structure of Au@Ag@SiO2 core-shell-shell NPs were optimized to maximize their optical and catalytic activities.