Nanoparticles, Nanochemistry

With the recent establishment of atomically precise nanochemistry, capabilities toward programmable control over the nanoparticle size and structure are being developed. Advances in the synthesis of atomically precise nanoclusters (NCs, 1-3 nm) have been made in recent years, and more importantly, their total structures (core plus ligands) have been mapped out by X-ray crystallography. These ultrasmall Au nanoparticles exhibit strong quantum-confinement effect, manifested in their optical absorption properties...

In the present work, the properties of ZnO nanoparticles obtained using an eco-friendly synthesis (biomediated methods in microwave irradiation) were studied. Saponaria officinalis extracts were used as both reducing and capping agents in the green nanochemistry synthesis of ZnO. Inorganic zinc oxide nanopowders were successfully prepared by a modified hydrothermal method and plant extract-mediated method. The influence of microwave irradiation was studied in both cases. The size, composition, crystallinity and morphology of inorganic nanoparticles (NPs) were investigated using dynamic light scattering (DLS), powder X-ray diffraction (XRD), SEM-EDX microscopy...

Cellular delivery of nitric oxide (NO) using NO donor moieties such as S-nitrosothiol (SNO) is of great interest for various applications. However, understandings of the intracellular decomposition routes of SNO toward either NO or ammonia (NH3 ) production are surprisingly scarce. Herein, the first report of SNO modified mesoporous organosilica nanoparticles with tetrasulfide bonds for enhanced intracellular NO delivery, ≈10 times higher than a commercial NO donor, is presented. The tetrasulfide chemistry modulates the SNO decomposition by shifting from NH3 to NO production in glutathione rich cancer cells...

Whereas heating nanoparticles with light is straightforward, measuring the resulting nanoscale temperature increase is intricate and still a matter of active research in plasmonics, with envisioned applications in nanochemistry, biomedicine, and solar light harvesting, among others. Interestingly, this research line mostly belongs to the optics community today because light is not only used for heating but also often for probing temperature. In this Perspective, I present and discuss recent advances in the search for efficient and reliable thermometry techniques for nanoplasmonic systems by the nano-optics community...

Temperature control is a recent development that provides an additional degree of freedom to study nanochemistry by liquid cell transmission electron microscopy. In this paper, we describe how to prepare an in situ heating experiment for studying the effect of temperature on the formation of gold nanoparticles driven by radiolysis in water. The protocol of the experiment is fairly simple involving a special liquid cell with uniform heating capabilities up to 100 °C, a liquid-cell TEM holder with flow capabilities and an integrated interface for controlling the temperature...

1D photonic crystals (1DPCs) are well known from a variety of applications ranging from medical diagnostics to optical fibers and optoelectronics. However, large-scale application is still limited due to complex fabrication processes and bottlenecks in transferring 1DPCs to arbitrary substrates and pattern creation. These challenges were addressed by demonstrating the transfer of millimeter- to centimeter-scale 1DPC sensors comprised of alternating layers of H3 Sb3 P2 O14 nanosheets and TiO2 nanoparticles based on a non-invasive chemical approach...

BACKGROUND: Despite advances in surgery, radiotherapy and chemotherapy, brain tumors are still a major health issue due to poor prognosis and high mortality rate. The current treatment options have limited efficiency. The main barriers to effective clinical treatment are systemic toxicity of cytotoxic compounds, the physical and functional barrier of the blood-brain barrier (BBB), and low selectivity of the therapeutic agents to tumor cells. OBJECTIVE: The study aimed to review the advances in targeted drug delivery systems and strategies for brain tumors...

Crystallization-induced photoluminescence weakening was recently revealed in ultrasmall metal nanoparticles. However, the fundamentals of the phenomenon are not understood yet. By obtaining conformational isomer crystals of gold nanoclusters, we investigate crystallization-induced photoluminescence weakening and reveal that the shortening of interparticle distance decreases photoluminescence, which is further supported by high-pressure photoluminescence experiments. To interpret this, we propose a distance-dependent non-radiative transfer model of excitation electrons and support it with additional theoretical and experimental results...

The principal goal of this work is to predict characteristics unique to equilibrated adsorption of a small number of molecules on atomic sites located inside a closed nanoscale space. Compared to the thermodynamic limit of macroscopic systems, significantly enlarged adsorbate coverage under nanoconfinement constitutes a major finding of the modeling. Concomitantly, nanoconfined adsorbates are expected to exhibit extra thermal stability against desorption. These effects on adsorption are explored using canonical partition-functions as well as an original relationship between coverage variations and the Langmuir constant, both in the frameworks of the ideal gas and lattice-gas models...

ConspectusSilica-based nanoparticles (SNPs) are a classic type of material employed in biomedical applications because of their excellent biocompatibility and tailorable physiochemical properties. Typically, SNPs are designed as nanocarriers for therapeutics delivery, which can address a number of intrinsic drawbacks of therapeutics, including limited bioavailability, short circulation lifetime, and unfavorable biodistribution. To improve the delivery efficiency and spatiotemporal precision, tremendous efforts have been devoted to engineering the physiochemical properties of SNPs, including particle size, morphology, and mesostructure, as well as conjugating targeting ligands and/or "gatekeepers" to endow improved cell selectivity and on demand release profiles...

Ligands are of tremendous importance for colloidal nanoparticles (NPs) in terms of surface protection, size and shape control, tailoring properties, self-assembly, and applications. However, it is very challenging to obtain unambiguous information on the ligands and their interactions and patterning on NPs. The recent advent of atomically precise nanochemistry has opened new horizons. One can now see ligands with atomic resolution and understand their behavior on the surface of ultrasmall NPs (1-3 nm) and also in their assemblies...

Isosbestic plasmonic nanostructures, which feature an invariance of optical absorption and heat generation upon varying the incident light polarization, have broad application in many fields such as nanochemistry, optical nanoantennas, and microbubble formation. In this study, we focus on the isosbestic optical absorption by metallic dimers and systematically investigate the coupling between two interacting particles by using both the superposition T-matrix method and dipole approximation model. We observe that the interparticle coupling effects on particle absorption can be both positive and negative, compared to an isolated particle...

This review provides a synthetic overview of the recent research advancements addressing the topic of catalysis with colloidal ruthenium metal nanoparticles through the last five years. The aim is to enlighten the interest of ruthenium metal at the nanoscale for a selection of catalytic reactions performed in solution condition. The recent progress in nanochemistry allowed providing well-controlled ruthenium nanoparticles which served as models and allowed study of how their characteristics influence their catalytic properties...

Nanoparticle-based antibiotic constructs have become a popular area of investigation in the biomedical sciences. Much of this work has pertained to human diseases, largely in the cancer therapy arena. However, considerable research has also been devoted to the nanochemistry for controlling infectious diseases. Among these are ones due to bacterial infections, which can cause serious illnesses leading to death. The onset of multi-drug-resistant (MDR) infections such as those caused by the human pathogen Staphylococcus aureus has created a dearth of problems such as surgical complications, persistent infections, and lack of available treatments...

Shape-specific copper oxide nanostructures have attracted increasing attention due to their widespread applications in energy conversion, sensing, and catalysis. Advancing our understanding of structure, composition, and surface chemistry transformations in shaped copper oxide nanomaterials during changes in copper oxidation state is instrumental from both applications and preparative nanochemistry standpoints. Here, we report the study of structural and compositional evolution of amorphous copper (II) hydroxide nanoparticles under hydrazine reduction conditions that resulted in the formation of crystalline Cu2 O and composite Cu2 O-N2 H4 branched particles...

A microreactor which can confine chemical reactions exclusively in tiny vessels with the volume of ~ 0.015 μm3 is introduced. Aluminum inversed hollow nanocone arrays (IHNAs) are fabricated by a simple and efficient colloidal lithography method. Ag and Au nanoparticles (NPs), as well as polypyrrole grow exclusively in the conic cavities under light illumination. The photocatalytic effect arising from the plasmonic enhanced electric fields (E-fields) of IHNAs boosts the reactions and in charge of the submicron site-selectivity...

The synthesis of alloys with long range atomic scale ordering (ordered intermetallics) is an emerging field of nanochemistry. Ordered intermetallic nanoparticles are useful for a wide variety of applications such as catalysis, superconductors, and mag-netic devices. However, the preparation of nanostructured ordered intermetallics is challenging in comparison to disordered alloys, hindering progress in materials development. We report a process for converting colloidally synthesized ordered inter-metallic PdBi2 to ordered intermetallic Pd3Bi nanoparticles under ambient conditions by an electrochemically induced phase transition...

The synthesis of well-defined inorganic colloidal nanostructures using functional macromolecules is an enabling technology that offers the possibility of fine-tuning the physicochemical properties of nanomaterials and has contributed to a broad range of practical applications. The utilization of functional reactive polymers and their colloidal assemblies leads to a high level of control over structural parameters of inorganic nanoparticles that are not easily accessible by conventional methods based on small-molecule ligands...

This paper reports hierarchical hybridization as a mode-mixing scheme to account for the unique optical properties of non-Bravais lattices of plasmonic nanoparticles (NPs). The formation of surface lattice resonances (SLRs) mediated by multi-order localized surface plasmons (LSPs) can result in asymmetric electric near-field distributions surrounding the NPs. This asymmetry is due to LSP hybridization at the individual NP level from LSPs of different orders and at the unit-cell level (NP dimer) from LSPs of the same order...

An easy-to-prepare ruthenium catalyst obtained from ruthenium(III) trichloride in water demonstrates efficient performances in the oxidation of several cycloalkanes with high selectivity toward the ketone. In this work, several physicochemical techniques were used to demonstrate the real nature of the ruthenium salt still unknown in water and to define the active species for this Csp3 -H bond functionalization. From transmission electron microscopy analyses corroborated by SAXS analyses, spherical nanoobjects were observed with an average diameter of 1...