Noble-metal nanoparticles (NMNPs) show great promise for their biomedical use. While it is known that surface ligands vastly impact their biological fate in vivo, the influence of ligand-core interactions remains underexplored. Herein, we showed that ultrasmall mercaptosuccinic acid (MSA)-coated gold/platinum (Au/Pt) alloy nanoparticles exhibited distinct in vivo targeting and clearance behaviors compared to their monometallic analogs, despite having identical surface ligands. Mechanistic studies revealed much stronger noncovalent ligand-core interactions in the alloy nanoparticles relative to the monometallic nanoparticles, due to intermetallic charge-transfer of the alloyed core. This enhanced ligand-core interaction further attenuated nanoparticle surface charge, leading to reduced serum protein adsorption and recognition by the mononuclear phagocyte system and eventually resulting in distinct in vivo behaviors. Our findings thus highlight the ligand-core interactions in regulating biological behaviors of NMNPs through affecting nanoparticle surface charge and protein adsorption, suggesting core composition as a tunable parameter for modulating the nano-bio interactions.

Localized surface plasmon resonance of noble metal nanoparticles provides an efficient mechanism for light-to-heat conversion, enabling the post-assembly manipulation of hollow polymer nanoshells in a 2D array. Rapid photothermal heating of gold nanoparticles decorated on the inner surface of nanoshells vaporizes the encapsulated solvent, inducing volumetric expansion and controlled positional adjustment of the nanoshells pre-assembled on a solid substrate. This process leads to significant improvements in array ordering, along with noticeable enhancements in optical diffraction intensity and a tunable redshift in structural color. The magnitude of this photothermal-induced expansion can be controlled by manipulating the incident light intensity and the polymer nanoshell parameters, such as diameter and thickness. This photoresponsive system offers a unique and versatile platform for light-controlled structural color manipulation, including direct laser writing and patterning, opening new opportunities for advanced materials with dynamically tunable optical properties.

The inadvertent deposition of latent fingerprints stamps indubitable forensic evidence, serving as a solid link between individuals and objective scenes. In this study, a novel approach was developed to simultaneously collect the geometrical and chemical features from latent fingerprints, which establishes a broadened perspective over the inspected biological traces. Ultrasonic spraying was employed to swiftly acquire a uniform distribution of noble metal nanoparticles (NPs) for surface-enhanced Raman spectroscopy (SERS) imaging. The NP-developed fingerprint brings an improved contrast of microscopic visualization as well as additional inelastic spectral information within the SERS image. K-NearestNeighbor (KNN) feature point matching and local similarity matching were utilized to recognize the SERS fingerprint images reconstructed from characteristic SERS bands. A matching score involving minutia descriptors was introduced to parametrize the degree of resemblance in latent fingerprint identification, yielding high matching accuracy even with partially damaged fingerprints. The trade-off between the accuracy in chemical identification and the completeness in fingerprint reconstruction was discussed. The effective SERS visualization and reconstruction of fingerprints was accomplished from the sample containing etomidate with the concentration as low as 1 μM. Additionally, the SERS imaging on a curved keycap surface was realized, which meets the critical demands of the investigation over particular chemicals.

A characteristic of many neurodegenerative disorders, such as Parkinson’s and Alzheimer’s, is amyloidogenic protein aggregation, for which there are currently no proven cures. Aging, mutation, and physiological stress can cause proteins to deviate from their natural folding patterns, potentially leading to the formation of hazardous protein aggregates. Noble metal nanoparticles (NPs), due to their unique physicochemical properties, have emerged as promising tools in biomedicine, with applications ranging from tissue engineering to drug delivery and diagnostics. Although concerns regarding cytotoxicity exist, small‐sized silver (Ag) NPs (AgNPs) have demonstrated potential in antiviral, anticancer, and antibacterial therapies. This study investigated the development of biocompatible AgNPs using a green synthesis approach and examined their chaperone‐like activity against protein aggregation, emphasizing the role of meticulous in vitro design. Human lysozyme (HLZ) served as a model protein for aggregation inhibition assays. Biogenic AgNPs exhibited a concentration‐dependent effect on HLZ aggregation, demonstrating an optimal inhibitory concentration, followed by a decrease in efficacy at higher concentrations. Furthermore, astrocytes treated with AgNPs displayed reduced protein aggregation, suggesting a chaperone‐like behavior. The initial phase focused on the detailed characterization of AgNPs synthesized using orange juice extract. Subsequently, this study explored the mechanistic understanding of AgNP‐mediated inhibition of protein aggregation under controlled conditions. A battery of biophysical techniques, including circular dichroism (CD), 8‐anilino‐1‐naphthalene‐sulfonic acid (ANS) fluorescence, thioflavin T (ThT) fluorescence, Congo red (CR) assay, and turbidity measurements, was employed to meticulously assess the inhibitory effect on HLZ aggregation in vitro.

The use of cationic quaternary ammonium halide as a surfactant is popular in aqueous seed-mediated growth methods of noble metal nanoparticles (NPs). Despite the effective shape control of NPs that can be achieved by modifying the surfactant chemistry, these structural parameters have been insufficiently probed. The number of cationic quaternary ammonium halide surfactants explored for the synthesis of Au NPs have been limited primarily to cetyltrimethylammonium bromide (CTAB) and cetyltrimethylammonium chloride (CTAC). In this study, we investigate the effect of structural parameters, including the headgroup, chain length, and counter-anion of the quaternary ammonium halides, on the resultant Au NPs formed using seed-mediated synthesis. By employing pentatwinned Au NPs as the starting seeds, we observe that (i) increasing the bulkiness of the surfactant headgroup results in the formation of Au NPs with fewer stellations and more shape polydispersity, (ii) surfactant chain length affects the dimension of Au NPs, and (iii) the counter-anion associated with the surfactant affects the Au NPs' final morphology. These structural parameters provide a practical handle to tune the shape, size, and polydispersity of the final Au NPs.

Background/Objectives: Research on noble metal nanoparticles (NPs) has increased over the past three decades, with advancements in synthesis techniques refining their physicochemical characteristics, including size, shape, and surface chemistry. Bimetallic NPs (BNPs) offer synergistic properties contributed by both metals. Gold (Au) and palladium (Pd) NPs possess low toxicity, high biocompatibility and loading, ease of synthesis and surface modification. Doxorubicin (DOX) and 5-fluorouracil (5-FU) are potent chemotherapeutic drugs but are rapidly metabolised in the body, producing severe side effects, limiting their use. Hence, innovative strategies to mitigate this is needed. Methods: In this study, AuPd NPs in a core-shell formation were chemically synthesized. The AuPd NPs were conjugated to 5-FU and DOX-encapsulated CS complexes and decorated with the targeting moiety transferrin (Tf). Results: Transmission electron microscopy and nanoparticle tracking analysis confirmed that the BNPs were spherical, with an average size of 73.4 nm. Functionalized BNPs were able to encapsulate more than 70% of 5-FU and DOX, resulting in a controlled drug release profile at pH 4.2. Cytotoxicity levels in human cancer cells, HeLa (cervical carcinoma) and MCF-7 (breast adenocarcinoma), as well as in non-cancer HEK293 (embryonic kidney) cells, revealed that the Tf-targeted nanocomplexes were HeLa cell-specific, with no significant cytotoxicity in the HEK293 cells. Tf-mediated cellular uptake was confirmed by receptor competition studies in the HeLa cells. Apoptosis and oxidative stress analysis confirmed cell death by apoptosis, consistent with the action of 5-FU and DOX. Conclusions: This study highlighted the potential of this BNP-nanocomplex as a suitable vehicle for drug delivery.

Constructing colloidal particles into designated hierarchies with integrated functionalities offers insights into bottom-up material fabrication. However, the arbitrary and controllable assembly of individual nanoscale and microscale particles remains highly challenging due to their diverse structural properties. Here, a general paradigm for the robust co-assembly of plasmonic noble metal nanoparticles and multifunctional polymer microspheres through thermodynamically driven heterocoagulation and coordination interactions is developed. Monodisperse poly(styrene-co-maleic anhydride) microspheres (PSMA MSs) are facilely synthesized using a one-step emulsification method with optional simultaneous encapsulation of magnetic and fluorescent nanoparticles. Upon surfactant removal, the purified PSMA MSs become metastable and trigger ultrafast co-assembly of silver nanocubes (AgNCs) onto MSs within 5min with the maximum coverage rate reaching nearly 50%. The densely immobilized AgNCs outside magnetic MSs exhibit excellent catalytic efficiency (>89% conversion across 15 cycles) and enable enzyme integration for cascade reactions. Moreover, the largest reported plasmonic-fluorescent encoded array (124 codes) is realized, achieving a significantly improved detection limit of 10 copies/reaction for respiratory viruses. This work addresses the long-standing challenge of achieving uniform distribution and dense immobilization of plasmonic noble metal nanoparticles and offers a general approach to fabricating designated hierarchies based on noble metal nanoparticles, with integrated functionalities for high-performance practical applications.

While the electromagnetic interaction between noble metal nanoparticles with adjacent molecules has been known for some time, the exact expression of the scattering, absorption, and extinction cross sections of such a system has long remained unspecified. Herein, these cross sections are analytically derived for a molecule-nanoparticle system in which the molecule is excited to a radiating dipole by monochromatic incident radiation. These analytic cross sections were used in numerical calculations to model the UV-vis spectrum of a 20nm gold nanoparticle colloid with attached IR-808 variant dye molecules. The numerical results compared favorably with experimental spectra.

We present a medium‐throughput synthesis approach for High Entropy Alloy (HEA) noble metal nanoparticles on conductive supports via electrodeposition. The presented method utilizes aqueous electrolyte solutions, exploiting high overpotentials to achieve mass transport‐controlled deposition. This ensures electrodeposition independent from individual equilibrium potentials of the different elements. Hydrogen evolution which interferes with electrodeposition is suppressed by operating in a pulsed mode at a mildly acidic pH. Applying the approach to the Au–Ir–Pt–Pd–Rh–Ru composition space, this study demonstrates that the developed method is fast, adaptable, and enables compositional control while maintaining a homogeneous element distribution. The mechanism of HEA nanoparticle synthesis is further investigated by examining material‐specific seed formation and diffusion phenomena. The results indicate that together with the electrolyte composition, seed formation as well as the diffusion of metal precursors in the aqueous phase govern the average composition of the synthesized HEA nanoparticles, while the formation enthalpies of element pairs explain the atomic‐scale segregation observed.

Due to their outstanding physicochemical properties, noble metal nanoparticles are widely exploited across multiple fields, including nanomedicine and sensors. In the nanostructure synthesis process, a stabilizing agent is usually introduced to prevent their aggregation. In this work, a poly-(N-isopropylacrylamide) (pNIPAM) thermosensitive polymer coating was synthesized in situ as a stabilizing layer during the formation of seed silver nanoparticles and characterized using UV-vis spectrophotometry and dynamic light scattering. The evolution of pNIPAM coating on the surface of seed silver nanoparticles was followed by studying the changes in the light extinction spectra of the nanoparticle solutions, caused by localized surface plasmon resonance and Rayleigh scattering. The sizes of the studied particles, determined by dynamic light scattering, indicate the formation of electrostatic chelate complexes of NIPAM or pNIPAM with silver ions or nanoparticles, which was confirmed by static and dynamic molecular mechanics (MMX) calculations in PCModel software.

Galvanic replacement reaction (GRR) is a versatile electrochemical strategy for constructing complex heterostructures. However, achieving controlled synthesis of noble-metal nanoparticles with defined morphologies and spatial distributions on an unconventional gallium-based liquid-metal (LM) surface remains highly challenging and largely unexplored. In this work, we systematically investigated the GRR between LM droplets and Pt precursors with different chloride coordination: K2PtCl4 ([PtCl4]2-, tetra-coordinated) and K2PtCl6/(NH4)2PtCl6 ([PtCl6]2-, hexa-coordinated). By deliberately exploiting the differences in thermodynamic driving forces and kinetic pathways associated with these ligand configurations, we demonstrate that the coordination environment of Pt complexes serves as an effective handle to regulate Pt nucleation and growth. Consequently, the [PtCl4]2- complex yields uniformly distributed, satellite-like Pt domains, whereas the [PtCl6]2- complex produces sparsely localized, patch-like Pt deposits. These distinct morphologies and deposition modes of Pt particles modulate interfacial stress, driving LM droplet evolution and divergent macroscopic transformations. In particular, the oxide layer formed on LM surfaces, together with Pt-catalyzed hydrogen evolution, was confirmed as a primary factor governing LM transformations across multiscale. Overall, this study deepens the fundamental understanding of LM-based GRR mechanisms and demonstrates a coordination-tuning strategy for designing noble-metal-coated LM heterostructures with tailored morphologies and spatial distributions, which could enable their use as reconfigurable functional materials in a broad range of applications.

Direct structural color printing enables the fabrication of customized patterns in a cost-effective manner without the need for complex procedures or costly equipment. However, it is still challenging to simultaneously achieve highly precise and stable structural color patterns while avoiding substrate damage and remaining both economical and environmentally sustainable. Here, a laser micro/nanoprinting strategy based on metal hydroxides is developed. An aluminum hydroxide ink is formulated to replace polymers or noble metal nanoparticles used in conventional color printing. Controllable growth of aluminum hydroxide with vivid structural colors is realized. The mechanism of laser-induced hydroxide growth and the correlation between processing parameters and structural colors are investigated. Customized color patterns and their applicability to information encryption and decryption are demonstrated. This strategy maintains the high precision of laser printing while avoiding substrate damage and costly or polluting inks, presenting great potential in designable structural colors.

Introduction: Plasmonic photothermal therapy (PPTT) with noble metal nanoparticles (NPs) have gained great relevance as less invasive platforms in the treatment of adenocarcinoma-type cancer tumors. The PPTT uses laser radiation to generate plasmonic effects in NPs that are distributed in the cancerous tissue, producing hyperthermia and cell death by apoptosis. Objective: To obtain two-dimensional temperature distributions and the associated cell damage distributions in tumoral tissue subjected to PPTT. Method: A numerical methodology based on Radial Basis Functions (RBFs) is implemented for solving the Pennes or bioheat equation and the Arrhenius and Three-state models for cellular damage estimation. The developed, validated and applied numerical methodology is based on the method of approximate particular solutions in local formulation (LMAPS). Results: The capability to solve problems with variable sources, multiple regions and different types of boundary conditions is shown by the comparison with OpenFOAM computational tool based on finite volume method and numerical results reported in the literature. This is performed by solving hypothetical situations of heat transfer in tissues including 1D and 2D domains with metabolic sources, perfusion term and radiation thermal conversion. Conclusions: The developed methodology is applied to a situation of PPTT in superficial tissue, from laser energy distribution description to the local percentage of cellular damage. This numerical methodology is the basis of the analysis, optimization and design of PPTT application processes in clinical environments considering its potential to solve complex geometries, time-varying boundary conditions and parameters and domains with multiple regions.

Abstract The chemical approach was used for the preparation of silver and gold nanoparticles assisted by ionic surfactant. In this study, trisodium citrate was utilized as an ionic surfactant to explore its ability as a linker or binder between silver/gold nanoparticles (AgNPs/AuNPs) and aminoglycoside antibiotic (amikacin). The resulting surfactant assisted AgNPs and AuNPs were characterized using various analytical techniques such as absorption spectroscopy (UV-Visible), diffraction method (X-ray diffraction) and Transmission electron microscopy (TEM) to examine the interaction process of the drug with nanoparticle surface. Findings revealed that citrate is not an effective mediator for amikacin binding to AgNPs surface in case of silver, as silver loses its surface plasmon resonance (SPR) following the introduction of amikacin results in the production of unstable sulphur compounds. The formation of unstable sulphur compounds is also confirmed from XRD pattern. In contrast, the XRD pattern for AuNPs showed a minor shift in each refection line, in comparison with bare AuNPs, when loaded with amikacin. Moreover, TEM analysis verified that there are no morphological changes in case of AuNPs after the formation of drug nanoconjugates. Therefore, citrate can act as an efficient bridge binding amikacin with the AuNPs surface.

PHEMA polymer brush/Ag nanoparticle hybrids for SERS analytics: characterization and performance as versatile sensing substrate.

FFF as a microfluidic platform for the streamlined optimization of ready-to-use nanozyme-labelled probes to enable robust and ultra-sensitive chemiluminescent bioassays.

Core-shell structure and twin-cone morphology of Au@Ag@HOF with efficient adsorption capability and high SERS enhancement efficiency for sensitive detection of bisphenol compounds in food.

Ultrafast laser synthesis of NIR-absorbing Au-TiO2 nanoagents for photothermal theranostics.

Catalytic membranes with integrated pore-confinement of ultrasmall noble metal nanoparticles: Realizing pollutant degradation in complex water matrices

Metal-oxide semiconductors (MOS) have emerged as versatile materials in a wide range of applications due to their tunable physicochemical properties and compatibility with various structural engineering strategies. Among the numerous MOS candidates, zinc oxide (ZnO) has gained significant attention because of its wide direct bandgap (~3.37 eV), large exciton binding energy (~60 meV), excellent thermal and chemical stability, strong ultraviolet absorption, and environmental non-toxicity. These attributes make ZnO a particularly attractive material for use in optoelectronic devices, transparent conductors, piezoelectric devices, photocatalysts, and chemical sensors. However, bulk ZnO materials suffer from inherent limitations such as low surface area, slow surface reaction kinetics, limited active sites, long carrier diffusion lengths, and poor defect tunability. These factors significantly restrict the efficiency and reliability of ZnO when used in high-performance gas sensing applications, particularly under ambient or humid conditions where sustainable responses are required. To overcome these challenges, the present study proposes a comprehensive strategy for enhancing the gas-sensing performance of ZnO through combined approaches involving dimensional modulation, nanostructuring, porosity control, noble metal functionalization, and nanoscale defect engineering. The goal of this study is to improve the response, selectivity, sensitivity, and stability of ZnO-based gas sensors under diverse environmental conditions. Initially, porous ZnO nanosheets were synthesized via a controlled hydrothermal method. The resulting nanosheets exhibited a sub-micron lateral dimension (~80 nm thickness) with ~16% porosity and an average pore size of ~60 nm. These nanostructures provided a specific surface area approximately three times higher than that of commercial ZnO nanoparticles, as confirmed by Brunauer–Emmett–Teller (BET) analysis. The increased surface area and porosity facilitate enhanced gas adsorption and diffusion. Photoluminescence (PL) spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis revealed a high concentration of oxygen vacancies (VO), which act as key active sites for gas interaction, thereby significantly improving sensing responses even in humid environments. To further enhance surface activity and electronic transport properties, noble metal nanoparticles were introduced. Noble metals are known to play a critical role in improving gas sensor performance through catalytic activity, charge transfer modulation, and Schottky barrier formation. Noble metal nanoparticles were uniformly loaded onto ZnO nanosheets through a one-pot hydrothermal synthesis route. The formation of Schottky junctions improved charge separation efficiency and enhanced chemical sensitivity. Subsequently, Au nanoparticles with a mean diameter of ~2 nm were rapidly deposited onto the ZnO surface using a microwave-assisted synthesis method that required less than one minute. This technique ensured high dispersion, scalability, and structural uniformity. The anchored Au nanoparticles increased the density of oxygen vacancies and facilitated electron transfer at the ZnO interface. This electronic and chemical sensitization effects led to a significant improvement in gas-sensing performance, especially in the presence of high relative humidity. In addition to noble metal functionalization, nanoscale defect engineering was employed to manipulate the electronic structure of ZnO and further enhance its sensing response. Nanogaps with an average width of ~2.2 nm were introduced along the (100) crystallographic planes of the porous ZnO nanosheets via a lithiation process using Li-ion implantation. This treatment resulted in a ~12% increase in surface oxygen vacancy concentration, accompanied by n-type doping behavior. Ultraviolet photoelectron spectroscopy (UPS) confirmed a reduction in the work function and an upward shift of the Fermi level, both of which contributed to improved charge transfer dynamics. These changes significantly accelerated the response and recovery times of the ZnO sensors and reduced the detection limit to trace levels, which are often required in practical sensing environments. The integration of morphological control, porous structure design, noble metal surface modification, and atomic-level defect tailoring allowed for the synergistic improvement of ZnO-based sensing devices across all key performance metrics: sensitivity, selectivity, response speed, recovery time, and long-term operational stability. Furthermore, all synthesis methods used in this study, such as hydrothermal, one-pot, and microwave-assisted techniques are scalable, low-cost, and compatible with existing semiconductor manufacturing processes, making them suitable for future commercial applications. In conclusion, this study demonstrates a multi-pronged, scalable, and effective strategy for optimizing ZnO as a high-performance gas-sensing material. The developed nanostructured and defect-engineered ZnO platforms exhibit superior physicochemical properties, rendering them highly promising for next-generation sensing technologies. The results not only highlight the practical value of combining noble metal functionalization and nanoscale defect modulation but also provide a design framework applicable to other metal-oxide semiconductor systems.