Deposition Of Nanoparticles Research Articles

Fast and in-situ electrodeposition of MXene/AuNPs composite for multiplexed and sensitive detection of infectious biomarkers using an electrochemical biosensor

Rapid, accurate, and cost-effective strategies for the multiplexed and quantitative detection of multiple infectious disease biomarkers are still lack in hospital. Here, we introduce a multiplexed screen-printed electrode for the simultaneous detection of three infectious disease biomarkers: HBsAg, anti-HIV, and anti-TP. The electrode modified with in-situ deposition of gold nanoparticles (AuNPs) and MXene multilayered nanosheets. Comprehensive characterization confirms the morphology and electrochemical response of the AuNPs&MXene modified screen-printed electrode (AuNPs&MXene-SPE). AuNPs&MXene composite contributes to enhance sensitivity by maximizing surface area and improving electron transfer efficiency. The AuNPs&MXene-SPE exhibits outstanding detection performance for HBsAg, anti-HIV, and anti-TP. The AuNPs&MXene-SPE sensors achieve broad detection ranges (0.05–1000 ng/mL for HBsAg, 0.35–140 ng/mL for anti-HIV, and 0.25–100 ng/mL for anti-TP) accompanied by low limits of detection (0.01, 0.11, and 0.10 ng/mL, respectively). Applied to standard serum samples, the sensors showcase precision with relative standard deviations consistently below 5.0 %, affirming their suitability for complex solution environments. These sensors offer notable advantages, including cost-effectiveness, rapid response, high sensitivity, and specificity, eliminating the necessity for expensive equipment, which open avenues for the realization of point-of-care testing (POCT).

Enhancement of copper nanoparticle yield in magnetron sputter inert gas condensation by applying substrate bias voltage and its influence on thin film morphology

Large-scale synthesis of high-purity nanoparticles is an intense topic of scientific research, with magnetron sputter inert gas condensation recognized as a promising, environmentally friendly technique avoiding wet chemical processes. This study explores the deposition of size-selected nanoparticles under varied substrate bias voltages and reports on a consequent increase in deposition rates up to 32 %. These alterations in substrate bias voltage induce a progressive change in the morphology of the resulting nanoparticle thin films, attributable to the increased kinetic energy of the nanoparticles. Comprehensive characterization via quadrupole mass spectroscopy of the nanoparticle flux, scanning electron microscopy, X-ray photoelectron spectroscopy, and low-energy ion scattering spectroscopy of the deposited nanoparticles corroborates the enhanced nanoparticle yield associated with increased substrate bias voltage. These findings signify a methodological advancement, enhancing the efficiency of magnetron sputter inert gas condensation and moving the technology a step further towards feasible industrial production.

Oxygen Vacancy-Enriched Alumina Stabilized Pd Nanocatalysts for Selective Hydrogenation of Phenols.

The prevalence of electronic defects has not been successfully demonstrated in nonreducible oxides. This work presents a straightforward approach to the preparation of a yellow alumina rich in F-centers (oxygen vacancies containing free electrons), which is well characterized by systematic spectral methods. The surface electron density of the as-prepared F-center enriched alumina sample was estimated to be approximately 0.35 mmol·g-1. Free electrons on the surface can reduce palladium precursors in situ, leading to the deposition of fine Pd nanoparticles on alumina. The produced Pd nanocatalysts are highly effective in the selective hydrogenation of phenol to cyclohexanone, achieving a high catalytic performance under mild conditions (30 °C and 0.1 MPa of H2). Systematic mechanism investigations reveal that hydroxyl radicals generated at the catalyst interfaces facilitate the activation of phenol. The activated phenol is then sequentially hydrogenated to give the intermediate 2-cyclohexenone and then the desired cyclohexanone. The catalyst system demonstrates efficacy in selectively hydrogenating substituted phenols into a wide array of functional ketones.

Engineering MXene Surface via Oxygen Functionalization and Au Nanoparticle Deposition for Enhanced Electrocatalytic Hydrogen Evolution Reaction.

MXene, a family of 2D transition metal carbides and nitrides, presents promising applications in electrocatalysis. Maximizing its large surface area is key to developing efficient non-noble-metal catalysts for the hydrogen evolution reaction (HER). In this study, oxygen-functionalized Ti3C2Tx MXene (Ti3C2Ox) is synthesized and deposited gold nanoparticles (Au NPs) onto it, forming a novel composite material, Au-Ti3C2Ox. By selectively removing other functional groups, mainly -O functional groups are retained on the surface, directing electron transfer from Au NPs to MXene due to electronic metal-support interaction (EMSI), thereby improving the catalytic activity of the MXene surface. Additionally, the interaction between Au NPs and -O functional groups further enhanced the overall catalytic activity, achieving an overpotential of 62 mV and a Tafel slope of 40.1 mV dec-1 at a current density of -10 mA cm-2 in 0.5 m H2SO4 solution. Density functional theory calculations and scanning electrochemical microscopy with ≤150 nm resolution confirmed the enhanced catalytic efficiency due to the specific interaction between Au NPs and Ti3C2Ox. This work provides a surface modification strategy to fully utilize the MXene surface and enhance the overall catalytic activity of MXene-based catalysts.

Making Mobile Nanotechnology Accessible: Is the Explicit Preparation of Janus Nanoparticle Necessary to Achieve Mobility?

This study compares the mobility behaviour, in a H2O2 environment, of three different geometries of hybrid particle made of silica core functionalized by gold (nanoparticles or layer). It is known that the decomposition of H2O2 on gold surfaces drives mobility; however, the link between mobility orientation and the organization of gold on silica surfaces is still questionable. While conventional wisdom posits that asymmetric designs are crucial for generating phoretic forces or localized bubble propulsion, recent research suggests that symmetrical particles may also exhibit motility. To address this debate, we developed a robust workflow for synthesizing gold grafted silica nanoparticles with precise control over size and shape, enabling the direct comparison of their motile behaviour by dynamic light scattering and particle tracking velocimetry. Our results indicate, first, that a combination of techniques is necessary to overcome their intrinsic limitation and, second, that the inherent asymmetry generated by isotropic gold nanoparticle deposition onto silica surfaces may enable particle motility.

Effect of gelatin nanoparticles’ size and charge on iontophoretic targeted deposition to the hair follicles

Hair follicles (HFs) represent a route of interest to drug delivery for treating several skin conditions. Iontophoresis, on the other hand, is a physical method to enhance drug permeation by applying a low electrical current to the formulation. HFs can be targeted following topical iontophoretic application, as they represent a pathway of lower electrical resistance, as well as a drug reservoir, in particular useful for nanoparticles (NPs), which can preferably accumulate in these structures. Combining both strategies may provide optimal results, but the literature still lacks evidence of the ideal NP characteristics for the iontophoretic drug delivery targeting the HFs. Here, we aimed to evaluate the effect of gelatin NPs’ size and charge under iontophoresis application on NPs’ deposition into the HFs. Four gelatin NP formulations were produced with varying gelatin concentrations and gelatin types (positively charged type A and negatively charged type B), with sizes ranging from 220 to 770 nm. A fluorescent dye, TRITC-dextran 150 kDa, was encapsulated for monitoring NPs deposition. Cutaneous penetration experiments were performed in vitro with and without iontophoresis for 6 h with pig ear skin. The deposition profile was assessed by confocal laser scanning microscopy. Photomicrographs showed a higher accumulation of the larger positively charged NPs (AL), reaching deeper portions of HFs, and showed iontophoresis further increased their deposition, resulting in the highest signal. In conclusion, these findings shed light on the applications of NPs and bring novel treatment opportunities for several diseases compromising the hair follicles.

Electroanalytical Probing of Triphasic Hydrogen Storage and Transport in Films of Nanoparticulate Polymer of Intrinsic Microporosity (PIM-1)

AbstractPreliminary experiments are reported to show quantitatively that hydrogen gas can be stored under triphasic conditions in wet nanoparticulate polymer of intrinsic microporosity (PIM-1) applied as a film to a platinum disk electrode surface. Based on chronoamperometric data, it is shown that the resulting triphasic interface is able to store hydrogen gas at apparent concentrations higher (3 orders of magnitude increase for an approx. 15 μm thick film with typically capp,hydrogen = 80 mM; Dapp,hydrogen = 1.2 × 10–11 m2s−1) than the known solubility of hydrogen gas in aqueous electrolyte (chydrogen = 0.08 mM; Dhydrogen = 5.0 × 10–9 m2s−1) at room temperature. Due to film roughness/heterogeneity, the apparent hydrogen concentration can only be estimated, but it increases with film thickness. At the same time the apparent diffusion coefficient is lowered considerably due to the molecularly rigid/glassy polymer host. The resulting modified electrode is investigated/proposed for energy storage applications with different amounts of PIM-1 nanoparticle deposits attached to the platinum surface. Graphical Abstract

Aromatic carboxyl acid regulated nanoparticle deposition and passivation of tin oxide for high performance perovskite solar cells

The composition and nano particle agglomeration of hydrolyzed species in chemical bath deposition (CBD) plays a key role in obtaining efficient SnO2 film for high performance perovskite solar cells (PSCs). In this work, the aromatic acids with varied carboxyl groups were investigated to regulate the nano particle deposition and passivate the buried SnO2/perovskite interface. The quasi in-situ dynamic light scattering and Zeta potential results indicated that the nano particle agglomeration with trimesic acid (TMA) was significantly refined throughout the whole deposition process. The TMA-SnO2 achieved an ideal energy band alignment with perovskite and released the internal residual strain, promoting the growth and crystallization of the perovskite film due to the corrdination of carboxyl groups. As a result, the interface defects were effectively passivated with enhanced efficiency and stability. The small area device based on TMA-SnO2 obtained an efficiency of 25.07 %. The devices with an enlarged area of 1.4 cm2 and the 5x5 cm2 mini-module (active area 10.054 cm2) showed impressive PCEs of 23.93 % and 22.40 %, respectively. Furthermore, the unencapsulated devices exhibit enhanced long-term stability, maintaining 80 % and 90 % of the initial efficiencies under 80 ± 5°C thermal annealing in nitrogen for 1176 h and in air condition for 3224 h, respectively.

An efficient catalytic method for the Suzuki reaction and oxidation of sulfides by using novel magnetic nanoparticles (SnFe2O4) as a reusable catalyst

In this study, we focused on the deposition of copper nanoparticles onto Cinchonine-functionalized SnFe2O4 magnetic nanoparticles. This environmentally friendly heterogeneous catalyst was thoroughly analyzed using a variety of techniques including SEM, EDS, TGA, TEM, VSM, XRD, ICP, XPS and FT-IR. In addition, it demonstrated outstanding performance as a catalyst for Suzuki reactions and the oxidation of sulfides in environmentally sustainable conditions. The catalyst could be effortlessly separated from the mixture and reused for up to four cycles without any decrease in its catalytic efficacy. This method provides the advantages of a simple procedure, high yields of products, convenient handling, environmentally friendly conditions, and short reaction times.

Engineered self-assembled protein nanosheets for in situ biosynthesis of peptide anchored protein-semiconductor hybrids for efficient hydrogen production

Catalytic hydrogen production using solar energy is of great significance in addressing the global energy crisis. Herein, an efficient artificial photocatalytic hydrogen production system based on hierarchical protein self-assembly is designed and developed by in situ biosynthesis of peptide-anchored protein-semiconductor hybrids. The self-grown protein-CdS quantum dot hybrids stabilize and array orderly by the predesigned bioengineered proteins assembled into monolayer nanosheets, perfectly mimicking both the structure and function of the natural photosynthetic system. By mild deposition of Pt nanoparticles, the photocatalytic hydrogen production performance of the system is further enhanced to 69100 μmolh−1 (Cd2+) g −1, 80 times the catalytic activity of free CdS. Remarkably, the protein 2D network effectively enhances the water solubility, dispersibility, and solution stability of the inorganic catalytic centers, affording efficient photocatalytic hydrogen evolution. The system maintains 91.2 % catalytic efficiency after 30 days. Furthermore, its hydrogen production rate can be artificially regulated between 69100 and 52100 μmolh−1 (per g Cd2+) by the assembly-disassembly process of the protein templates. Thus, our work showcases the importance of the protein template and its assembly in maintaining the structural stability and high catalytic performance of the photocatalytic system and provides promising ideas for the simulation of natural photosynthetic systems.

Polyol Synthesis of Bimetallic FePt Nanoparticles over h-BN Substrate

Hexagonal boron nitride (h-BN) is a promising support for the deposition of functional metallic nanoparticles for next generation of catalysts. Multicomponent metallic NPs, such as bimetallic FePt NPs, are attracting much attention as catalytically active sites because their properties can be superior to their single-element counterpart. To achieve the best catalytic properties, careful control of the chemical composition of the bimetallic NPs on the surface of h-BN substrates is necessary. Herein we report the development of a polyol synthesis protocol that elucidates the relationship between the initial and resulting Fe:Pt molar ratio in a FePt/h-BN material. TEM, STEM, EDXS, BET and BJH methods were utilized to characterize the surface and structure of the h-BN support and FePt/h-BN heterostructures.

Uptake of Magnetite Nanoparticles on Polydopamine Films Deposited on Gold Surfaces: A Study by AFM and XPS.

Polydopamine has the capacity to adhere to a large variety of materials and this property offers the possibility to bind nanoparticles to solid surfaces. In this work, magnetite nanoparticles were deposited on gold substrates coated with polydopamine films. The aim of this work was to investigate the effects of the composition and morphology of the PDA layers on the sticking of magnetite nanoparticles. The polydopamine coating of gold surfaces was achieved by the oxidation of alkaline solutions of dopamine with various reaction times. The length of the reaction time to form PDA was expected to influence the composition and surface roughness of the PDA films. Magnetite nanoparticles were deposited on these polydopamine films by immersing the samples in aqueous dispersions of nanoparticles. The morphology at the nanometric scale and the composition of the surfaces before and after the deposition of magnetite nanoparticles were investigated by means of AFM and XPS. We found that the amount of magnetite nanoparticles on the surface did not vary monotonically with the reaction time of PDA formation, but it was at the minimum after 20 min of reaction. This behavior may be attributed to changes in the chemical composition of the coating layer with reaction time.

CeO2 loaded on L-tryptophan functionalized graphitic carbon nitride colorimetric-fluorescent dual-channel detection

In this study, a nanocomposite with CeO2 loaded on L-tryptophan functionalized graphitic carbon nitride (CeO2/L-g-C3N4) was developed by a facile two-step method. Firstly, L-tryptophan functionalized graphitic carbon nitride (L-g-C3N4) was achieved via π-π stacking interactions through a physical ultrasonic treatment process, which had better dispersibility in water than Bulk-g-C3N4. Then the final product of CeO2/L-g-C3N4 was obtained by a hydrothermal co-precipitation technique with cerium nitrate as precursor. The characterization of morphology indicated that CeO2 nanoparticles evenly distributed on the surface of CeO2/L-g-C3N4, which might be attributed to L-tryptophan offering more bonding sites (–COOH) for the deposition of nanoparticles. The material exhibited excellent oxidase-mimicking activity, which could catalyze the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) into the blue-colored oxidized TMB product (oxTMB), and a new hydroquinone (HQ) colorimetric sensing strategy was proposed. And theoretical simulations indicate that the increased enzymatic activity is mainly attributable to the reduced binding energy of absorbed intermediates. Additionally, due to the material’s exceptional fluorescence properties, combined with the inner filter effect and redox reactions, a unique on–off-on fluorescence sensing mechanism had been successfully developed for the detection of Cr(VI) and SO32−.

Combined Role of {001} Facet-Enriched Morphology and Gold Nanoparticle Deposition on Anatase TiO2 Photoactivity.

The interplay on anatase TiO2 photoactivity between particle morphology and gold nanoparticles (NPs) deposition, via either deposition-precipitation (DP) or photodeposition (P), is here investigated by evaluating the photoactivity of Au modified anatase (Au/TiO2) nanocrystals with either a pseudospherical shape or a nanosheet structure in both reduction and oxidation test reactions. The presence of Au NPs on the anatase surface only slightly affects its photoactivity in Cr(VI) reduction, which is kinetically limited by the anodic half-reaction, whereas a larger exposure of highly oxidant {001} facets is beneficial for overcoming this rate-determining step. In the photocatalytic oxidation of both formic acid, proceeding through a direct mechanism, and rhodamine B (RhB) on surface fluorinated photocatalysts, occurring through a hydroxyl-radical-mediated mechanism, the presence of gold NPs produces a significant photoactivity increase only with spherically shaped photocatalysts, mainly exposing {101} facets. These results are rationalized in light of the preferential migration of photogenerated, oppositely charged carriers toward different crystal facets. In fact, when the Au/TiO2 material mainly exposes the more oxidant {001} facets, where photoproduced holes preferentially migrate, recombination between these latter and the electrons captured by Au NPs is favored. Instead, Au NPs on {101} facets efficiently capture photopromoted electrons, preferentially migrating toward such facets with a consequent improvement of photoproduced charge separation.

RuCo@C Hollow Nanoprisms Derived from ZIF-67 for Enhanced Hydrogen and Oxygen Evolution Reactions.

Zeolitic imidazolate frameworks (ZIFs) are commonly used to create complex hollow structures for energy applications. This study presents a simple method to produce a novel hollow nanoprism Co@C hierarchical composite from ZIF-67 through high-temperature treatment at 800 °C. This composite serves as a platform for Ru nanoparticle deposition, forming RuCo@C hollow nanoprism (RuCo@C HNP). As an electrocatalyst in 1 M KOH, RuCo@C HNP exhibits excellent hydrogen evolution reaction (HER) performance, with a low overpotential of 32 mV to reach 10 mA cm-2, a Tafel slope of 39.67 mV dec-1, a high turnover frequency (TOF) of 3.83 s-1 at ƞ200, and stable performance over 50 h. It also achieves a low ƞ10 of 266 mV for the oxygen evolution reaction (OER) with a Tafel slope of 45.22 mV dec-1. Density functional theory (DFT) calculations reveal that Ru doping in Ni/Co maintains a low water dissociation barrier, reduces the energy barrier for the OER rate-determining step, and creates active sites for H*, enhancing adsorption/desorption abilities. These results are attributed to the synergy between Co and Ru and the hollow prism structure's increased surface area. This method for synthesizing hollow structures using ZIF composites shows promise for applications in the energy sector.

In situ synthesis and deposition of palladium nanoparticles on gas diffusion layers via gamma radiolysis for cathode electrodes in proton exchange membrane fuel cells

This study investigates gamma radiolysis technique for synthesising and depositing palladium (Pd) nanoparticles on gas diffusion layers (GDLs). The Pd-coated GDLs were then used to fabricate MEAs, which were evaluated for their single-cell performance. The fabricated PEMFCs with Pd-loaded GDLs successfully generated potential and produced electricity, with the PEMFC with a Pd-loaded GDL prepared using a 0.05 M Pd precursor solution and 50 KGy dose achieved performances comparable to the PEMFC with commercial gas diffusion electrodes (GDEs). This study represents the first demonstration of a functional PEMFC using a novel gamma radiolysis-synthesised Pd catalyst GDL as the cathode electrode.

Surface-tension-directed gate functionalization in organic electrochemical transistor for wearable sweat lactate monitoring

Wearable sweat lactate detection holds significant potential for applications in healthcare and exercise performance evaluation. Organic electrochemical transistors (OECTs) is emerging as an efficient platform in wearable lactate sensing by integrating an electron transfer interface between the electrode and the bio-catalytic layer. In this study, we demonstrated a wearable OECT designed for dynamic lactate monitoring in sweat through a one-step deposition of gold nanoparticles (Au NPs) on the gate electrode. Utilizing the simple surface-tension-directed deposition strategy, this method ensures a uniform distribution of Au NPs with high catalytic activity, enabling rapid and sensitive lactate signal transition. Herein, the OECT device exhibits a linear detection range for sweat lactate from tens of micromolars to hundreds of millimolars (r² > 0.97), along with high selectivity and long-term stability in human sweat. Furthermore, we successfully employed this flexible OECT sensor for real-time lactate monitoring system during various physical activities, highlighting its potential for non-invasive evaluation of fatigue and exercise performance in athletes. This work provides an easy-to-use prototype for continuous physiological monitoring, enhancing personalized healthcare and training management.

MXene-based nanozymes remodel tumor microenvironment for heterojunction-enhanced sonodynamic and chemodynamic therapy to boost robust cancer immunotherapy

Reactive oxygen species (ROS)-mediated sonodynamic therapy (SDT) holds increasing potential in treating deep-seated tumor owing to the high tissue-penetration depth, but hardly controls remote metastasis. To trigger robust cancer immunotherapy against malignant metastatic cancers, we report the rational construction of Z-scheme heterojunctions through decorating biocompatible Co3O4 nanoparticles with multiple enzyme-like catalytic activities onto Ti3C2Tx nanosheets to realize the augmented SDT and chemodynamic therapy (CDT). The deposition of Co3O4 nanoparticles not only sensitizes the sonodynamic activity of Ti3C2Tx nanosheets owing to the regulation of separation dynamics of electron-hole pairs, but also achieves the cascade amplification of ROS generation through Co2+-mediated Fenton-like reaction, Co3+-facilitated GSH depletion, and catalytic decomposition of endogenous H2O2 to relieve hypoxia. More importantly, the immunosuppressive TME could be reversed by the greatly enhanced ROS levels, ultimately inducing immunogenic cell death that promotes robust systemic immune responses. The heterojunction-enhanced SDT and CDT via Co3O4@Ti3C2Tx could trigger robust cancer immunotherapy, which achieves the eradication of primary tumors and suppression of distant tumors. This work highlights the potential of heterojunction engineering-enhanced SDT and CDT to trigger robust cancer immunotherapy.

Enhancing interfacial locking of the CF and PBPESK resin by in-situ electrochemical deposition of MOF nanoparticles

The interfacial bonding of carbon fiber reinforced polymer composites plays a critical role in the overall performance of the composites. Poor interfacial bonding leads to catastrophic damage of composites when subjected to external loads. In this study, three-dimensional (3D) NH2-UiO-66 nanoparticles in-situ synthesis on the carbon fiber (CF) surface using an electrochemical method was achieved facilely and efficiently to enhance the interfacial adhesion of CF/PBPESK composites. The influence of incorporating 3D NH2-UiO-66 nanoparticles into the interphase on the interfacial and mechanical properties of carbon fiber reinforced composites was systematically investigated. The NH2-UiO-66 nanoparticles significantly increased the carbon fibers surface energy. The flexural, interlaminar shear and interfacial shear strength of the N–CF–6min/PBPESK composite were improved by 19 %, 31 %, and 93 %, respectively, compared to the D-CF/PBPESK composite. Furthermore, the interfacial failure mechanism of the composites was investigated. This approach offered a simple and efficient strategy for the in-situ synthesis of interfacial phase characterized by robust mechanical locking effects.

Impact of nano-Y2O3 on the physical, microstructure, and mechanical characteristics of Cu composite fabricated via powder metallurgy

This investigation focused on optimizing the adhesion of Y2O3 nanoparticles for uniform distribution within a copper matrix. Five samples were prepared with varying Y2O3 content (0 %, 2.5 %, 5 %, 7.5 %, and 10 % by weight). To enhance bonding, a 5 % nano silver coating was applied to the Y2O3 particles. The electroless deposition of copper nanoparticles onto the Y2O3 surface ensured even distribution within the matrix. The composite powders were then compressed at 700 MPa and sintered at 950 °C for 140 minutes. Density verification and microstructural analysis using scanning electron microscopy revealed a uniform distribution. Increasing the Y2O3 content gradually improved hardness, while wear rate measurements using a pin-on-disc method indicated a decrease with higher Y2O3 ratios. Additionally, electrical and thermal conductivity, along with the coefficient of thermal expansion, showed reductions with increasing Y2O3 content. This comprehensive approach provided valuable insights into the structural, mechanical, and conductive properties of the synthesized materials.