Hybrid Nanoclusters Research Articles

Thermal‐Cascade Multifunctional Therapeutic Systems for Remotely Controlled Synergistic Treatment of Drug‐Resistant Bacterial Infections

AbstractAntimicrobial therapy remains one of the major global challenges, particularly in the absence of effective treatment strategies for drug‐resistant bacteria. In this study, a comprehensive treatment approach is proposed for drug‐resistant bacterial wound infections based on the development of thermal‐cascade multifunctional therapeutic systems (MTSs), spanning from the design of functional nanoscale materials to macroscopic smart hydrogel. Within the MTSs, functional antibiotic‐loaded hybrid nanoclusters enable targeted therapeutic delivery and synergistic mild hyperthermia‐antibiotic treatment, strongly suppressing drug‐resistant bacteria while demonstrating excellent biocompatibility with normal cells and tissues. Furthermore, near‐infrared irradiation can trigger the photothermal effects of hybrid nanoclusters to induce gelation of thermal‐sensitive hydrogel, forming MTSs to serve as highly adaptable, drug‐enriched protective dressings for infected wounds. Both in vitro and in vivo results substantiate that MTSs enhance the bioavailability of therapeutic agents (including bacterial internalization and tissue penetration), exert synergistic effects to completely eradicate drug‐resistant bacteria, promoted wound healing and revascularization, and demonstrate excellent biocompatibility. This work offers an innovative demonstration to address drug‐resistant bacterial infections through the advancement of sophisticated material systems.

Development of Pd/In2O3 hybrid nanoclusters to optimize ethanol vapor sensing.

In this study, we successfully synthesize palladium-decorated indium trioxide (Pd/In2O3) hybrid nanoclusters (NCs) using an advanced dual-target cluster beam deposition (CBD) method, a significant stride in developing high-performance ethanol sensors. The prepared Pd/In2O3 hybrid NCs exhibit exceptional sensitivity, stability, and selectivity to low concentrations of ethanol vapor, with a maximum response value of 101.2 at an optimal operating temperature of 260 °C for 6 at% Pd loading. The dynamic response of the Pd/In2O3-based sensor shows an increase in response with increasing ethanol vapor concentrations within the range of 50 to 1000 ppm. The limit of detection is as low as 24 ppb. The sensor exhibits a high sensitivity of 28.24 ppm-1/2, with response and recovery times of 2.7 and 4.4 seconds, respectively, for 100 ppm ethanol vapor. Additionally, the sensor demonstrates excellent repeatability and stability, with only a minor decrease in response observed over 30 days and notable selectivity for ethanol compared to other common volatile organic compounds. The study highlights the potential of Pd/In2O3 NCs as promising materials for ethanol gas sensors, leveraging the unique capabilities of CBD for controlled synthesis and the catalytic properties of Pd for enhanced gas-sensing performance.

Copper-containing POM-based hybrid P2Mo22V4Cu4 nanocluster as heterogeneous catalyst for the light-driven hydroxylation of benzene to phenol.

The current traditional phenol production process has many shortcomings, and the efficient and clean photocatalytic one-step oxidation to phenol is gradually attracting attention. Heteropolyacids (PMo10V2) with high-density Lewis acid active sites and excellent photoelectron transfer ability are ideal choices for catalytic reactions. In this study, a copper-modified isolated dimeric hybrid nanocluster, [Cu(pyim)2]2[Cu(pyim)2(P2MoVI20MoV2VIV4O82)]2·(H2O) (pyim = [2-(pyridin-2-yl)imidazole]), was synthesized by a convenient hydrothermal method. The structural analysis demonstrated that the compound was composed of metal-organic complexes containing pyim ligands, Keggin-type heteropolyacids, and transition metal copper ions. Remarkably, this not only solves the difficulty that the heteropolymeric acid cannot be recovered by dissolving in the solvent but also introduces the copper atom as a second active center. The catalyst exhibited a benzene conversion of 15.6% and a selectivity of 85.2% in a mixed solution of acetonitrile and acetic acid under optimal reaction conditions. After four catalytic cycles, the PXRD pattern proved that the catalyst was still stable. This study provides a good idea for photocatalytic reactions and other environmental applications.

Amorphous BaTiO3 Electron Transport Layer for Thermal Equilibrium‐Governed γ‐CsPbI3 Perovskite Solar Cell with High Power Conversion Efficiency of 19.96%

Compared to organic–inorganic hybrid perovskites, the cesium‐based all‐inorganic lead halide perovskite (CsPbI3) is a promising light absorber for perovskite solar cells owing to its higher resistance to thermal stress. Nonetheless, additional research is required to reduce the nonradiative recombination to realize the full potential of CsPbI3. Here, the diffusion of Cs ions participating in ion exchange is proposed to be an important factor responsible for the bulk defects in γ‐CsPbI3 perovskite. Calculations based on first‐principles density functional theory reveal that the [PbI6]4− octahedral tilt modifies the perovskite crystallographic properties in γ‐CsPbI3, leading to alterations in its bandgap and crystal strain. In addition, by substituting amorphous barium titanium oxide (a‐BaTiO3) for TiO2 as the electron transport layer, interfacial defects caused by imperfect energy levels between the electron transport layer and perovskite are reduced. High‐resolution transmission electron microscopy and electron energy loss spectroscopy demonstrate that a‐BaTiO3 forms entirely as a single phase, as opposed to Ba‐doped TiO2 hybrid nanoclusters or separate domains of TiO2 and BaTiO3 phases. Accordingly, inorganic perovskite solar cells based on the a‐BaTiO3 electron transport layer achieved a power conversion efficiency of 19.96%.

A potential application of a novel synergistic catalytic nanocluster system composed of biological enzymes and nanozyme in glycerol bioconversion

The integration of multimodal chemical/biocatalysis technology has provided a broad prospect in the efficiency of cascade reactions for a long time. Inspired by the intricate structure and superior efficiency of natural multi-enzyme systems, it is attractive for developing the next generation of high-performance orderly enzyme cascade biological platforms, combined with the catalase-like activity and immobilization properties of nanozymes. In our simple and convenient design, a biomimetic multi-enzyme hybrid nanocluster with excellent catalytic activity was synthesized by in-situ adsorption and immobilization of biological enzyme on nanozyme Fe3O4@OA. The combination of nanozyme Fe3O4@OA with single enzyme (concatenated alditol oxidase, catAldO) or double enzymes (catAldO and concatenated dihydroxy-acid hydrolyase, catDHAD) enjoys outstanding synergistic biocatalytic ability. Nanozyme Fe3O4@OA alternatives catalase to catalyze H2O2 cycle and regenerate O2, which implements the internal circulation of O2 → H2O2 → O2 system and accelerates the conversion of glycerol. It realized the high efficiency synergistic catalysis of nanozyme and biological enzyme successfully. In contrast to simple biocatalyst mixtures in solution, the prepared multienzyme hybrid resulted in the obvious improvements in activity for tandem reactions. The cascade bioactivity of the multienzyme complex was enhanced by the synergistic effect of the immobilization of nanozyme Fe3O4@OA, the opening of substrate channel between the enzyme and nanozyme, and the effective reduction of the transport distance among intermediate metabolites. In this study, it highlights the superiority of synergistic bioreactor integrated with nanoclusters contain Fe3O4@OA nanozyme and biological enzyme, realizing rapid recovery and multiple reusability of nanoclusters, and suggesting great application potential in multi-enzyme synergistic cascade catalysis.

Nanocluster-Based Drug Delivery and Theranostic Systems: Towards Cancer Therapy.

Over the last decades, the global life expectancy of the population has increased, and so, consequently, has the risk of cancer development. Despite the improvement in cancer therapies (e.g., drug delivery systems (DDS) and theranostics), in many cases recurrence continues to be a challenging issue. In this matter, the development of nanotechnology has led to an array of possibilities for cancer treatment. One of the most promising therapies focuses on the assembly of hierarchical structures in the form of nanoclusters, as this approach involves preparing individual building blocks while avoiding handling toxic chemicals in the presence of biomolecules. This review aims at presenting an overview of the major advances made in developing nanoclusters based on polymeric nanoparticles (PNPs) and/or inorganic NPs. The preparation methods and the features of the NPs used in the construction of the nanoclusters were described. Afterwards, the design, fabrication and properties of the two main classes of nanoclusters, namely noble-metal nanoclusters and hybrid (i.e., hetero) nanoclusters and their mode of action in cancer therapy, were summarized.

Novel Trends in MXene/Conducting Polymeric Hybrid Nanoclusters

Novel Trends in MXene/Conducting Polymeric Hybrid Nanoclusters

Gold(III) Aryl Complexes as Reagents for Constructing Hybrid Peptide-Based Assemblies via Cysteine S-Arylation.

Organometallic complexes have recently gained attention as competent bioconjugation reagents capable of introducing a diverse array of substrates to biomolecule substrates. Here, we detail the synthesis and characterization of an aminophosphine-supported Au(III) platform that provides rapid and convenient access to a wide array of peptide-based assemblies via cysteine S-arylation. This strategy results in the formation of robust C-S covalent linkages and is an attractive method for the modification of complex biomolecules due to the high functional group tolerance, chemoselectivity, and rapid reaction kinetics associated with these arylation reactions. This work expands upon existing metal-mediated cysteine arylation by introducing a class of air-stable organometallic complexes that serve as robust bioconjugation reagents enabling the synthesis of conjugates of higher structural complexity including macrocyclic stapled and bicyclic peptides as well as a peptide-functionalized multivalent hybrid nanocluster. This organometallic-based approach provides a convenient, one-step method of peptide functionalization and macrocyclization, and has the potential to contribute to efforts directed toward developing efficient synthetic strategies of building new and diverse hybrid peptide-based assemblies.

Photocatalytic Activity of Cellulose Acetate Nanoceria/Pt Hybrid Mats Driven by Visible Light Irradiation.

A photocatalytic system for the degradation of aqueous organic pollutants under visible light irradiation is obtained by an innovative approach based on ceria/platinum (Pt) hybrid nanoclusters on cellulose acetate fibrous membranes. The catalytic materials are fabricated by supersonic beam deposition of Pt nanoclusters directly on the surface of electrospun cellulose acetate fibrous mats, pre-loaded with a cerium salt precursor that is transformed into ceria nanoparticles directly in the solid mats by a simple thermal treatment. The presence of Pt enhances the oxygen vacancies on the surface of the formed ceria nanoparticles and reduces their band gap, resulting in a significant improvement of the photocatalytic performance of the composite mats under visible light irradiation. Upon the appropriate pretreatment and visible light irradiation, we prove that the most efficient mats, with both ceria nanoparticles and Pt nanoclusters, present a degradation efficiency of methylene blue of 70% and a photodegradation rate improved by about five times compared to the ceria loaded samples, without Pt. The present results bring a significant improvement of the photocatalytic performance of polymeric nanocomposite fibrous systems under visible light irradiation, for efficient wastewater treatment applications.

Real-time time-dependent density functional theory implementation of electronic circular dichroism applied to nanoscale metal-organic clusters.

Electronic circular dichroism (ECD) is a powerful spectroscopy method for investigating chiral properties at the molecular level. ECD calculations with the commonly used linear-response time-dependent density functional theory (LR-TDDFT) framework can be prohibitively costly for large systems. To alleviate this problem, we present here an ECD implementation within the projector augmented-wave method in a real-time-propagation TDDFT framework in the open-source GPAW code. Our implementation supports both local atomic basis sets and real-space finite-difference representations of wave functions. We benchmark our implementation against an existing LR-TDDFT implementation in GPAW for small chiral molecules. We then demonstrate the efficiency of our local atomic basis set implementation for a large hybrid nanocluster and discuss the chiroptical properties of the cluster.

Synthesis and characterization of nanoclusters: Inorganic-organic hybrid copper and cobalt containing arsenotungstates(III) with lone pair on heteroatom incorporating bidentate N-donating ligands

Three inorganic-organic hybrid nanoclusters of copper and cobalt containing arsenotungstates with lone pair on heteroatom have been synthesized under mild reactions conditions. All the compounds have been characterized by single crystal X-ray diffraction, Fourier transform infrared, UV/visible spectroscopy, thermogravimetric and field emission scanning electron microscopic (FE-SEM) analysis. The compound [NaRb{Cu(phen) (H 2 O) 2 Cl} 2 ][{Cu(phen)(H 2 O)} 2 {Cu(phen) (H 2 O)Cl} 2 {Cu 2 As 2 W 19 O 67 (H 2 O)] (1a) is a sandwiched type arsenotungstate with two copper atoms in square planar environment in the belt region. The polyanion- 1 is decorated by four copper phenanthroline complexes through a terminal oxygen atom of the polyanion. In addition, two other cobalt containing inorganic-organic hybrid lone pair containing arsenotungstates(III) with 1,10-phenanthroline [NaRbCo(phen) 3 ][{Co(phen)(H 2 O) 3 }CoAs 2 W 20 O 67 (H 2 O) 3 ] (2a) and 2,2’-bipyridine[Na 3 RbCo(2,2-bipy) 3 ][CoAs 2 W 20 O 67 (H 2 O) 3 ] (3a) has also been synthesized under mild conditions. The polyanion ( 2 ) is a mono cobalt substituted sandwiched type structure that is decorated by a cobalt phenanthroline complex attached to the polyanion through a terminal oxygen atom. Meanwhile the other complex ( 3 ) is also a monocobalt substituted sandwiched type structure which contains a cobalt 2,2’-bipyridine complex in the cationic part. Polyanion- 1 shows intermolecular π-π stacking interaction between the phenanthroline ligand in the cationic part and one that is attached directly to the polyanion. The compounds are also characterized by FE-SEM analysis and the compound 3a shows ultra- smooth cuboids with grain size in the range of 1 to several micrometer though some very small irregular particles with the size of a few micrometer were also observed.

An Organometallic Strategy for Assembling Atomically Precise Hybrid Nanomaterials.

For decades, chemists have strived to mimic the intricate design and diverse functions of naturally occurring systems through the bioinspired synthesis of programmable inorganic nanomaterials. The development of thiol-capped gold nanoparticles (AuNPs) has driven advancement in this area; however, although versatile and readily accessible, hybrid AuNPs are rarely atomically precise, which limits control over their surface topology and therefore the study of complex structure-function relationships. Here, we present a bottom-up approach to the systematic assembly of atomically precise hybrid nanoclusters employing a strategy that mimics the synthetic ease with which thiol-capped AuNPs are normally constructed, while producing well-defined covalent nanoscale assemblies with diverse surface topologies. For the first time, using a structurally characterized cluster-based organometallic building block, we demonstrate the systematic synthesis of nanoclusters with multivalent binding capabilities to complex protein targets.

Self-Defined Transition State in Hybrid C70–Au Clusters Created by the Scanning Tunneling Microscope Tip

Manipulation of C70–Au hybrid nanoclusters was investigated using a scanning tunneling microscope (STM) tip. We demonstrate that removing a selected C70 molecule from the cluster by STM-tip resulted in an intermediate transition state without thermal decomposition. The molecule rotates and diffuses around the cluster and leaves the cluster without taking an additional molecule and Au atoms due to the rather weak interaction between molecules and the surface atoms. After removing a C70 molecule, the van der Waals interaction among the remaining C70 molecules leads to reorganization of the cluster. This self-transition-state is due to a weak charge transfer between the molecules and the surface. The extraction of molecules in a ring cluster resulted in polygonal Au island formation.

Polysaccharide-Hydrophobic Nanoparticle Hybrid Nanoclusters for Enhanced Performance in Magnetic Resonance/Photoacoustic Imaging.

Polysaccharide-nanoparticle (NP) hybrid nanoclusters have great potential to revitalize diverse bioapplications; however, fabricating polysaccharide-based hybrid nanoclusters composed of high-quality NPs generated in the organic phase remains a challenge. Here, using calcium alginate as a polysaccharide/tetramethylammonium hydroxide (TMAOH) combination, we report a novel approach to the design of alginate-hydrophobic magnetic-plasmonic core-shell (MPCS) NP hybrid nanoclusters (A-MPCS HNCs). Furthermore, we observe the dependence of the formation of A-MPCS HNCs on the TMAOH concentration. The enhanced performance in both magnetic resonance r2 relaxivity and photoacoustic (PA) signals and the biocompatibility/bioactivity as well as the in vivo performance of A-MPCS HNCs shows them to be a promising magnetic resonance/photoacoustic dual-mode imaging agent. Our strategy could open doors to the use of other precious high-quality nanomaterials created in the organic phase via well-established synthetic chemistry in the design of alginate-hydrophobic nanomaterial hybrid nanoclusters, giving rise to novel and multifarious bioapplications.

Nanoclusters prepared from ruthenium(II) and quercetin for fluorometric detection of cobalt(II), and a method for screening their anticancer drug activity.

Ruthenium-quercetin conjugated nanoclusters (Ru-QC NCs) were synthesized via a one-pot reflux reaction. As inhalation of heavy metal ions like cobalt can lead to lung cancer, a fluorescent probe was designed for the determination of Co(II) both in aqueous solutions and living cells. The probe consists of hybrid nanoclusters with an average size of 2nm that were prepared from ruthenium(II) ions and the flavonoid quercetin. These are termed as Ru-QC NCs. They display strong orange-colored emission with a peak at 558nm under 465-nm excitation. The Ru-QC NCs are cell viable and enable imaging of cells and intracellular fluorometric detection of Co(II). The anticancer properties of Ru-QC NCs were screened by using non-small cell lung cancer (A549) and human dermal fibroblast (HDFa) cell lines. The Ru-QC NCs exert considerable cytotoxicity in A549 cells (at levels of 20-50μg·mL-1), whereas no significant cytotoxicity was observed in case of HDFa cells. The anticancer properties of Ru-QC NCs were screened via MTT assay, live-dead staining, and ROS assay, respectively. Morphological changes of cancer cells were observed using atomic force microscopy. The fluorescent probe can detect Co(II) with a detection limit of 9.28nM and with a linear response in the 0.03-100μM concentration range. Graphical abstract Schematic representation of ruthenium-quercetin nanoclusters with potential anticancer properties. They are promising fluorescent probes for intracellular sensing of cobalt (Co2+) and bio-imaging. They exhibited efficient fluorometric detection of Co2+ with the limit of detection (LOD) of 9.28nM.

3D conductive NiCo/NiCoOx hybrid nanoclusters modified with amorphous FeOOH nanosheets for sensitive nonenzymatic glucose sensor

Developing a cost-effective electrocatalyst with high activity and excellent stability is very significant to nonenzymatic glucose detection. Herein, we have constructed 3D NiCo/NiCoOx nanocluster electrode modified by amorphous FeOOH nanosheets owing to the similar electrocatalytic activity of FeOOH to natural peroxidases. The NiCo nanoclusters can provide an excellent conductivity and high active surface areas, while the amorphous two-dimensional ultrathin structure of FeOOH stimulates more open metal sites for glucose oxidation. Besides, the strong synergetic effects among ternary Fe, Ni and Co are beneficial to the transport of charge. Though comprehensive electrochemical measurements, it is found that the as-prepared electrode possesses the prominent activity toward glucose oxidation with high sensitivity of 7138 µA mM−1 cm−2, a wide linear range of 1 µM and 8 mM, a low detection limit of 0.82 µM, good selectivity and excellent stability, all of which is mainly derived from the more active sites, rapid mass transport and superior electron transfer. This research provides a model system for developing more available electrocatalysts for glucose detection.

Sn-SnO2 hybrid nanoclusters embedded in carbon nanotubes with enhanced electrochemical performance for advanced lithium ion batteries

Sn-based materials are one promising high-capacity anode material for lithium-ion batteries. The practical application of Sn-based materials is generally restricted by their significant capacity fading due to the volume expansion and structural changes during Sn alloying/dealloying process. In this work, Sn-SnO2 hybrid nanoclusters are embedded into carbon nanotube network, forming a Sn-SnO2@CNT composite. The Sn-SnO2 nanoclusters are consisted of interconnected Sn and SnO2 nanocrystals, in which SnO2 forms a beneficial environment for the alloying/dealloying of Sn. The ultrafine particle size of SnO2 (<10 nm) also allows a highly reversible conversion reaction, contributing to high overall capacities. The Sn-SnO2 nanoclusters are uniformly dispersed in CNT matrix, therefore providing abundant active sites for Li-ion storage. The CNT matrix functions in improving electrical conductivity, preventing Sn aggregation, and accommodating Sn volume change in prolonged cycles. As a result, the hybrid Sn-SnO2@CNT electrode shows excellent rate capability (1059 mAh g−1 at 1 A g−1 and 960 mAh g−1 at 5 A g−1, corresponding to 0.53 mAh cm−2 at 0.5 mA cm−2 and 0.48 mAh cm−2 at 2.5 mA cm−2) and outstanding cycling stability (86% capacity retention after 1000 cycles at 0.5 A g−1), making it an promising anode material for high-performance lithium-ion batteries.

Facile Synthesis of Ag‐TiO2 Hybrid Nanocluster:A Comprehensive Experimental and Computational Insight into the Role of Surface Ligands on Enhanced Visible Light Photo‐catalysis

AbstractOwing to their ultrafine size, biocompatibility and excellent photo‐stability, metallic nanoclusters are promising materials which could be combined with ultra‐small TiO2 to discover a new class of hybrid nanomaterial with unique photocatalytic and self‐cleaning properties. A lot of effort has been made very recently to combine silver nanoclusters (AgNC) with titania and hence size and composition controlled electronic and catalytic properties. However, most of the methods used extended network of titania to support AgNC and individual titania functionalized AgNC is rarely observed. In the present study, we report a new low temperature method of preparation of ultra‐small TiO2 functionalized AgNC ligated with glutathione. AgNC alone shows negligible visible light photocatalysis whereas incorporation of ultra‐small titania, lowers the bandgap of the hybrid nanocluster and facilitate solar activation leading to enhanced catalytic activity. Visible light induced catalytic property of hybrid NCs are investigated in degradation of a model dye, Rhodamine B (RhB). Simple structural models Agm(SCH3)n‐TiO2 are used to explore the interaction of surface ligands with TiO2 molecule using Density Functional Theory (DFT) calculations. The calculated absorption spectra using Time Dependent Density Functional Theory (TD‐DFT) have been used for monitoring the spectral shifts of characteristics absorption bands towards visible region.

Tuning morphology and conductivity in two-step synthesis of zinc-cobalt oxide and sulfide hybrid nanoclusters as highly-performed electrodes for hybrid supercapacitors

We reported a facile two-step hydrothermal procedure to prepare zinc-cobalt oxide and sulfide hybrid nanoclusters (ZCOSH NCs), initialized by the synthesis of metal oxides and followed by the partial substitution of oxygen with sulfur. Benefiting from their morphological features and partial substitution with sulfur, both the electrical conductivity and further the actual specific capacitance of ZCOSH NCs were apparently improved compared to zinc-cobalt binary oxide nanosheets (ZCO NSs). Moreover, its cycling stability has also been significantly enhanced. Its excellent specific capacitance achieved 2176.7 F g−1 at 1 A g−1, which was six times larger than ZCO NSs (367.2 F g−1 at 1 A g−1). Moreover, a hybrid supercapacitor was assembled using ZCOSH NCs as its positive electrode and the activated carbon as its negative electrode. This hybrid supercapacitor device presented a higher specific capacitance value of 116.3 F g−1 at 1 A g−1 with corresponding specific energy of 41.4 W h kg−1 at a specific power of 801.3 W kg−1, and a superior cycling stability after 3000 charge-discharge cycling tests. This study confirmed the feasible and unique synthesis approach to balance the higher capacitance of oxides and the higher electric conductivity of sulfides within this binary ZCOSH NC.

Programmable Assembly of Hybrid Nanoclusters.

Hybrid nanoparticle clusters (often metallic) are interesting plasmonic materials with tunable resonances and a near-field electromagnetic enhancement at interparticle junctions. Therefore, in recent years, we have witnessed a surge in both the interest in these materials and the efforts to obtain them. However, a versatile fabrication of hybrid nanoclusters, that is, combining more than one material, still remains an open challenge. Current lithographical or self-assembly methods are limited to the preparation of hybrid clusters with up to two different materials and typically to the fabrication of hybrid dimers. Here, we provide a novel strategy to deposit and align not only hybrid dimers but also hybrid nanoclusters possessing more complex shapes and compositions. Our strategy is based on the downscaling of sequential capillarity-assisted particle assembly over topographical templates. As a proof of concept, we demonstrate dimers, linear trimers, and 2D nanoclusters with programmable compositions from a range of metallic nanoparticles. Our process does not rely on any specific chemistry and can be extended to a large variety of particles and shapes. The template also simultaneously aligns the hybrid (often anisotropic) nanoclusters, which could facilitate device integration, for example, for optical readout after transfer to other substrates by a printing step. We envisage that this new fabrication route will enable the assembly and positioning of complex hybrid nanoclusters of different functional nanoparticles to study coupling effects not only locally but also at larger scales for new nanoscale optical devices.