Volume 90, Issue 9

The ability to track and quantify changes in oxygen concentration as a function of disease progression or therapy is crucial to advance targeted chemotherapeutics. New non-invasive sensors must be developed that are small enough to penetrate into tissue and monitor dynamic changes with high resolution in real time. One way to address this challenge is with the use of nanoparticle-based sensors. This review details the design, synthesis, and characterization of optical oxygen sensors that combine a fluorescent semiconductor quantum dot (QD) with an oxygen-responsive phosphorescent molecule. The QD may have multifaceted roles in these constructs, serving as an internal standard for ratiometric sensing, as an antenna for multiphoton absorption, and as an energy transfer donor for the attendant phosphorescent molecule. Solid-state devices may be prepared by embedding the two components in a polymer matrix. Alternatively, solution-phase sensors can be synthesized by covalent conjugation, self-assembly in organic solvents, or micelle encapsulation in aqueous media. Several sensors have been used for biological imaging and oxygen sensing, demonstrating that these constructs can quantify oxygen in biological systems.

Photocatalytic water splitting for hydrogen evolution as an attractive strategy for developing sustainable energy by utilizing sunlight has attracted enormous research efforts. Cadmium sulfide (CdS) with visible light response and proper energy band structure has been studied intensively. To suppress the recombination of charge carriers and facilitate the hydrogen evolution reaction (HER) over CdS, electrically conductive graphene and active-site-abundant MoS 2 have proven to be efficient dual cocatalysts to improve the photocatalytic HER performance of CdS. In this review, we will focus on the representative ternary composite photocatalysts of CdS-graphene-MoS 2 . The synthesis approaches are first summarized, followed by the discussion of the roles of each component in the composites. Then main attention will be paid to highlighting the effects of the microscopic structures of the components on the photocatalytic performance of the composites for HER applications. It is expected that this review could be helpful to the rational design and further optimization of semiconductor-based composite photocatalysts through materials engineering strategies for solar energy conversion.

The field of plasmonics has grown at an incredible pace in the last couple of decades, and the synthesis and self-assembly of anisotropic plasmonic materials remains highly dynamic. The engineering of nanoparticle optical and electronic properties has resulted in important consequences for several scientific fields, including energy, medicine, biosensing, and electronics. However, the full potential of plasmonics has not yet been realized due to crucial challenges that remain in the field. In particular, the development of nanoparticles with new plasmonic properties and surface chemistries could enable the rational design of more complex architectures capable of performing advanced functions, like cascade reactions, energy conversion, or signal transduction. The scope of this short review is to highlight the most recent developments in the synthesis and self-assembly of anisotropic metal nanoparticles, which are capable of bringing forward the next generation of plasmonic materials.

Chemists are often regarded as “architects”, who are capable of building up complex molecular structures in the ultrasmall-dimensional world. However, compared with organic chemistry, nanochemistry – which deals with nanoparticles in the size range from 1 to 100 nm – is less precise in terms of synthesis, composition, and structure. Such an imprecise nature of nanochemistry has impeded an in-depth understanding as well as rational control of structures and properties of nanomaterials. Motivated by this, thiolate-protected gold nanoclusters (denoted as Au n (SR) m ) have recently emerged as a paradigm of atomically precise nanomaterials, in which all the nanoparticles are identical to each other with the same number of core atoms ( n ) and surface ligands ( m ) as well as the atomic arrangement. In this review, we provide a demonstration of how the precise nature of Au n (SR) m nanoclusters allows one to understand, decipher and discover some important, enigmatic and intriguing issues and phenomena in nanoscience, including (i) a precise nanoscale transformation reaction induced by surface ligand exchange, (ii) the total structures of crystalline metal phases and the self-assembled surface monolayers, (iii) the periodicities and quantum confinement in nanoclusters and (iv) the emergence of hierarchical complexity in the entire nanoparticle system. We expect that such an in-depth understanding will eventually lead to the rational design and precise engineering of complex architectures at the nanoscale.

Flavonoid structures, found in nature or obtained by synthesis, may be very complex. These Recommendations provide a guide for flavonoid aglycone names. This will also allow the construction of the names for their polyglycosylated species with clarity and conciseness. A joint working party of IUPAC/IUBMB members has prepared these recommendations, which establish rules for the general nomenclature of flavonoids, providing examples of acceptable trivial names, and names derived from trivial names, together with semi-systematic and fully systematic names that follow the published IUPAC recommendations.

The concept of Electrical Energy per Order ( E EO ) was introduced in 2001 as a figure of merit for evaluating the energy requirements of ultraviolet-based advanced oxidation processes (UV AOPs) used for the degradation of various organic contaminants. The E EO parameter represents the energy input into the reactor that can achieve an order of magnitude decrease in the concentration of a target contaminant in a unit volume. Since the introduction of this parameter, it has become increasingly popular among UV AOP researchers and practitioners. However, the E EO is often reported without important details that affect the parameter, making its interpretation difficult. The E EO depends on a variety of factors ( e.g. the concentration and identity of the target contaminant and the amount of hydrogen peroxide added). Therefore, the E EO parameter needs to be reported in the literature with several other experimental details affecting the reactor performance and in a way that proper comparisons can be made between reactors across studies or manufacturers. This paper discusses the proper application of the E EO parameter for bench-, pilot-, and full-scale studies. Sucralose (artificial sweetener, C 12 H 19 Cl 3 O 8 ) is proposed as a standard substance for reactor comparison.