Chemical versatility of azide radical: journey from a transient species to synthetic accessibility in organic transformations

The generation of azide radical (N₃˙) occurs from its precursors primarily via a single electron transfer (SET) process or homolytic cleavage by chemical methods or advanced photoredox/electrochemical methods. This in situ generated transient open-shell species has unique characteristic features that set its reactivity. In the past, the azide radical was widely used for various studies in radiation chemistry as a 1e^- oxidant of biologically important molecules, but now it is being exploited for synthetic applications based on its addition and intermolecular hydrogen atom transfer (HAT) abilities. Due to the significant role of nitrogen-containing molecules in synthesis, drug discovery, biological, and material sciences, the direct addition onto unsaturated bonds for the simultaneous construction of C-N bond with other (C-X) bonds are indeed worth highlighting. Moreover, the ability to generate O- or C-centered radicals by N₃˙ via electron transfer (ET) and intermolecular HAT processes is also well documented. The purpose of controlling the reactivity of this short-lived intermediate in organic transformations drives us to survey: (i) the history of azide radical and its structural properties (thermodynamic, spectroscopic, etc.), (ii) chemical reactivities and kinetics, (iii) methods to produce N₃˙ from various precursors, (iv) several significant azide radical-mediated transformations in the field of functionalization with unsaturated bonds, C-H functionalization via HAT, tandem, and multicomponent reaction with a critical analysis of underlying mechanistic approaches and outcomes, (v) concept of taming the reactivity of azide radicals for potential opportunities, in this review.

Study and quantification of enantiodiscrimination power of four polymeric chiral LLCs using NAD 2D-NMR

Identifying and understanding the role of key molecular factors involved in the orientation/discrimination phenomena of analytes in polymer-based chiral liquid crystals (CLCs) are essential tasks for optimizing computational predictions (molecular...

Benzannulation Reactions: A Case for Perspective Change From Arene Decoration to Arene Construction

Benzannulation reactions involve construction of a benzene ring from acyclic precursors. This class of reactions offer a versatile and often superior alternative to aromatic substitution for construction of substituted arenes. Selected pioneering and recent reports of various benzannulation reactions are categorised and discussed in this review.

Solution-processed two-dimensional materials for next-generation photovoltaics

In the ever-increasing energy demand scenario, the development of novel photovoltaic (PV) technologies is considered to be one of the key solutions to fulfil the energy request. In this context, graphene and related two-dimensional (2D) materials (GRMs), including nonlayered 2D materials and 2D perovskites, as well as their hybrid systems, are emerging as promising candidates to drive innovation in PV technologies. The mechanical, thermal, and optoelectronic properties of GRMs can be exploited in different active components of solar cells to design next-generation devices. These components include front (transparent) and back conductive electrodes, charge transporting layers, and interconnecting/recombination layers, as well as photoactive layers. The production and processing of GRMs in the liquid phase, coupled with the ability to "on-demand" tune their optoelectronic properties exploiting wet-chemical functionalization, enable their effective integration in advanced PV devices through scalable, reliable, and inexpensive printing/coating processes. Herein, we review the progresses in the use of solution-processed 2D materials in organic solar cells, dye-sensitized solar cells, perovskite solar cells, quantum dot solar cells, and organic-inorganic hybrid solar cells, as well as in tandem systems. We first provide a brief introduction on the properties of 2D materials and their production methods by solution-processing routes. Then, we discuss the functionality of 2D materials for electrodes, photoactive layer components/additives, charge transporting layers, and interconnecting layers through figures of merit, which allow the performance of solar cells to be determined and compared with the state-of-the-art values. We finally outline the roadmap for the further exploitation of solution-processed 2D materials to boost the performance of PV devices.

Base-promoted, CBr4-mediated tandem bromination/intramolecular Friedel-Crafts alkylation of N-aryl enamines: a facile access to 1H- and 3H-indoles

Described here is a general and highly efficient method for the synthesis of 1H- and 3H-indoles. In the presence of CBr₄ and a suitable base, the cyclization of N-aryl enamines proceeds with high efficiency. Unlike previous intramolecular cross dehydrogenative coupling (CDC) of the same substrates, this process does not require the use of either a transition metal or a stoichiometric amount of oxidant. This method also features operational simplicity, easy scalability and good substrate tolerability. Control experiments indicate the reactions may proceed in a tandem sequence of bromination and intramolecular Friedel-Crafts alkylation in a simple one-pot procedure.

Nano-targeting lessons from the SARS-CoV-2

The lack of targeting efficacy has frequently led functionalized nanoparticles to accumulate in unwanted cells and tissues while boosting toxicity-related effects. Conversely, viruses are natural nanoparticles that precisely and responsively interact with the biological machinery through an effective-driven fashion. This interaction is enhanced by a meticulous spatial arrangement which results in a quasi-crystalline distribution of proteins on the viruses' surface. Amidst the COVID-19 pandemic, we propose to look at the SARS-CoV-2 nanoscale viral scaffold as an example of a highly-ordered architecture that must inspire and tailor the production of targeted synthetic nanoparticles.

Comparison of the scavenging capacities of phloroglucinol and 2,4,6-trihydroxypyridine towards HO˙ radical: a computational study

In this work the scavenging capacities of biologically active phloroglucinol (1,3,5-trihydroxybenzene, THB-OH) and structurally similar 2,4,6-trihydroxypyridine (THP-OH) towards HO˙ were examined. This task was realized by means of density functional theory, through investigation of all favorable antioxidative pathways in two solvents of different polarity: benzene and water. It was found that in benzene both compounds conform to the hydrogen atom transfer (HAT) and radical adduct formation (RAF) mechanisms. In water, the mechanisms of antioxidative action of the investigated compounds are far more complex, especially those of THB-OH. This compound and HO˙ undergo all four investigated mechanisms: HAT, RAF, sequential proton loss electron transfer (SPLET), and single electron transfer-proton transfer (SET-PT). HAT, RAF and SPLET are operative mechanisms in the case of THP-OH. Independently of solvent polarity, both investigated compounds are more reactive towards HO˙ in comparison to Trolox. Our final remark is as follows: the electron-withdrawing effect of the nitrogen is stronger than the electron-donating effect of the OH groups in the molecule of THP-OH. As a consequence, THB-OH is more powerful antioxidant than THP-OH, thus implying that the presence of nitrogen decreases the scavenging capacity of the respective compound.

Core-shell nanowire arrays based on ZnO and CuxO for water stable photocatalysts

Staggered gap radial heterojunctions based on ZnO-Cu_xO core-shell nanowires are used as water stable photocatalysts to harvest solar energy for pollutants removal. ZnO nanowires with a wurtzite crystalline structure and a band gap of approximately 3.3 eV are obtained by thermal oxidation in air. These are covered with an amorphous Cu_xO layer having a band gap of 1.74 eV and subsequently form core-shell heterojunctions. The electrical characterization of the ZnO pristine and ZnO-Cu_xO core-shell nanowires emphasizes the charge transfer phenomena at the junction and at the interface between the nanowires and water based solutions. The methylene blue degradation mechanism is discussed taking into consideration the dissolution of ZnO in water based solutions for ZnO nanowires and ZnO-Cu_xO core-shell nanowires with different shell thicknesses. An optimum thickness of the Cu_xO layer is used to obtain water stable photocatalysts, where the ZnO-Cu_xO radial heterojunction enhances the separation and transport of the photogenerated charge carriers when irradiating with UV-light, leading to swift pollutant degradation.

Sonochemistry-assisted fabrication of 1D-ZnSb2O6@2D-MoS2 nanostructures: A synergistic energy storage material for supercapacitors

In this work, a novel nanohybrid composing of molybdenum disulphide nanosheets and zinc antimonate nanorods was fabricated using ultrasonication assisted homogenous magnetic stirring approach and investigated their electrochemical performance as an electrode material for supercapacitors. First and foremost, the structural, vibrational, morphological, optical and chemical compositional characteristics of the fabricated nanohybrid electrode material were investigated. Subsequently, the electrochemical properties of the nanohybrid electrode were explored using CV, GCD and EIS studies in 1.0 M KOH solution. The fabricated nanohybrid electrode material exhibited tremendous electrochemical performance by distributing maximum specific capacitance of 469.28 F g^-1 at a current density of 5.0 A g^-1 with high cycling stability of 102.0% even after 2000 cycles at a current density of 10.0 A g^-1. These exceptional electrochemical characteristics of MoS₂/ZnSb₂O₆ nanocomposites are ascribed to the influence of ultrasonication on non-aggregated nanocomposite formation, existence of more number of electrochemical active sites and synergistic interactions between two different nanostructures. The acquired results confirmed that MoS₂/ZnSb₂O₆ nanocomposites could be a prospective and electrochemically active candidate as electrode materials for supercapacitors.

Construction of in situ self-assembled FeWO4/g-C3N4 nanosheet heterostructured Z-scheme photocatalysts for enhanced photocatalytic degradation of rhodamine B and tetracycline

Although photocatalytic degradation is an ideal strategy for cleaning environmental pollution, it remains challenging to construct a highly efficient photocatalytic system by steering the charge flow in a precise manner. In this work, a novel, highly efficient, stable, and visible light active hybrid photocatalytic system consisting of FeWO4 and g-C3N4 nanosheets (CNNs) has been successfully prepared by an in situ self-assembly solvothermal approach. Several characterization techniques were employed to study the phase structures, morphologies, optical properties, surface composition and chemical state of the as-prepared samples. SEM and TEM results demonstrated that the FeWO4 nanoparticles are uniformly dispersed on the surface of CNNs with a diameter of about 10-20 nm, which could provide maximum interfacial contact and a synergistic coupling effect between FeWO4 and CNNs. XPS and FTIR results confirmed that there was strong electrostatic interaction between FeWO4 and CNNs, suggesting the formation of heterojunctions between them. In addition, UV-DRS and PL spectroscopy revealed that the FeWO4/CNN composites exhibited increased visible light absorption and improved charge generation/separation efficiency. As a result, the photocatalytic activity of the FeWO4/CNNs was enhanced in comparison with pure FeWO4 and CNNs for rhodamine B (RhB) and tetracycline (TC) degradation under natural sunlight irradiation. The photocatalytic efficiency of the optimal FeWO4/CNN composite (10 wt% FeWO4/CNNs) for the degradation of RhB (TC) was about 13.26 (4.95) and 86.2 (31.1) times higher than that of pure FeWO4 and CNNs, respectively. Meanwhile, the 10 wt% FeWO4/CNN sample exhibits good photocatalytic stability in recycling experiments. The enhanced photocatalytic activity may be attributed to the formation of the Z-scheme system between FeWO4 and CNNs, effectively prolonging the lifetime of the photoexcited electrons generated by CNNs and the photoexcited holes generated by FeWO4, which was subsequently confirmed by the active species trapping experiments and the calculation of relative band alignments. This work opens up a new feasible avenue to synthesize visible light active Z-scheme photocatalysts for application in energy production and environmental remediation.

Application of dialkyl azodicarboxylate frameworks featuring multi-functional properties

The application of dialkyl azodicarboxylates as versatile reagents in Mitsunobu, oxidation, electrophilic, amination and carbonylation reactions is reviewed.

Robust Sandwich-Structured Nanofluidic Diodes Modulating Ionic Transport for an Enhanced Electrochromic Performance

Biomimetic solid-state nanofluidic diodes have attracted extensive research interest due to the possible applications in various fields, such as biosensing, energy conversion, and nanofluidic circuits. However, contributions of exterior surface to the transmembrane ionic transport are often ignored, which can be a crucial factor for ion rectification behavior. Herein, a rational design of robust sandwich-structured nanofluidic diode is shown by creating opposite charges on the exterior surfaces of a nanoporous membrane using inorganic oxides with distinct isoelectric points. Potential-induced changes in ion concentration within the nanopores lead to a current rectification; the results are subsequently supported by a theoretical simulation. Except for providing surface charges, functional inorganic oxides used in this work are complementary electrochromic materials. Hence, the sandwich-structured nanofluidic diode is further developed into an electrochromic membrane exhibiting a visual color change in response to redox potentials. The results show that the surface-charge-governed ionic transport and the nanoporous structure facilitate the migration of Li+ ions, which in turn enhance the electrochromic performance. It is envisioned that this work will create new avenues to design and optimize nanofluidic diodes and electrochromic devices.

Facile preparation of partially reduced graphite oxide nanosheets as a binder-free electrode for supercapacitors

Preparation of graphene (GR) based electrode materials with excellent capacitive properties is of great importance to supercapacitors. Herein, we report a facile approach to prepare partially reduced graphite oxide (PRG) nanosheets by reducing graphite oxide (GO) using commercial Cu2O powder as a reduction agent, moreover, we demonstrate that the PRG nanosheets can act as building blocks for assembling hydrogels (PRGH) and flexible film (PRGF). The obtained PRGH and PRGF can be directly used as binder-free electrodes for supercapacitors and give high specific capacitance (292 and 273 F g-1 at a current density of 0.5 A g-1 in a three-electrode system, respectively) due to the existence of oxygen-containing functional groups in PRG nanosheets. PRG also gives excellent rate ability and cycle stability. This study suggests a facile pathway to produce GR-based materials with excellent capacitive properties and is meaningful for flexible supercapacitors.

Ferromagnetic nanoparticle-embedded hybrid nanogenerator for harvesting omnidirectional vibration energy

A new form of generator known as the triboelectric nanogenerator (TENG) has recently been suggested as a simple and low-cost solution to scavenge ambient mechanical energy. Although there have been substantial advances in TENGs over the past few years, the power efficiency of TENGs must be enhanced further before they can be practically applied. In the present study, we report a ferromagnetic nanoparticle-embedded hybrid nanogenerator (FHNG) which operates based on both triboelectricity and electromagnetic induction. A TENG and an electromagnetic generator (EMG) efficiently cooperate to generate electrical energy from the same motion, i.e., the vibration of a synthesized nanoparticle. A surface-functionalized ferric oxide nanoparticle, which has strong ferromagnetism and high triboelectricity, was produced by a simple surface-coating process. The measured electrical characteristics revealed that the output voltage of both the TENG and the EMG components increased by approximately 50 times and by twofold, respectively, after the surface functionalization step. Moreover, when constant vibration of 3 Hz is applied to the fabricated FHNG, the TENG and EMG components correspondingly generated output power of 133.2 μW at a load resistance of 100 MΩ and 6.5 μW at a load resistance of 200 Ω. The output power per unit mass from the FHNG is greater than that according to the arithmetic sum of the individual TENG and EMG components, demonstrating synergy between the two components. Furthermore, the device can generate stable output under various vibration directions, amplitudes, and frequencies due to the fluid-like characteristics of the powder. The packaged structure also securely protects the device from external humidity and dust. Connected to a rationally designed power management circuit, a digital clock was turned on solely by the fabricated FHNG.

High electrochemical performance of 3D highly porous Zn0.2Ni0.8Co2O4 microspheres as an electrode material for electrochemical energy storage

3D highly porous Zn_0.2Ni_0.8Co₂O₄ microspheres unveil superior electrochemical energy storage properties.

A novel trimeric cationic surfactant as a highly efficient capping agent for the synthesis of trisoctahedral gold nanocrystals

A trimeric cationic surfactant, even at a very low concentration of 0.2 mM, enables the formation of trisoctahedral Au nanocrystals.

Simultaneous modulation of surface composition, oxygen vacancies and assembly in hierarchical Co3O4 mesoporous nanostructures for lithium storage and electrocatalytic oxygen evolution

We developed a facile solution reductive method to simultaneously tune the surface composition, oxygen vacancies and three dimensional assembly in Co₃O₄ hierarchical nanostructures. The controllable surface composition, oxygen vacancies together with hierarchical micro/nanoarchitectures resulted in superior electrochemical properties when used as the anode materials for lithium-ion batteries and as an electrocatalyst for the oxygen evolution reaction. The excellent electrochemical performance is attributed to the synergistic effects of novel hierarchical morphology, crystal structure of the active materials, the improvement of intrinsic conductivity and inner surface area induced by the oxygen vacancies. The present strategy not only provides a facile method to assemble novel hierarchical architectures, but also paves a way to control surface structures (chemical composition and crystal defects) in other transition-metal compounds, and thus will hold great promise in the fields of energy storage and conversion.

An enhanced electrochemical and cycling properties of novel boronic Ionic liquid based ternary gel polymer electrolytes for rechargeable Li/LiCoO2 cells

A new generation of boronic ionic liquid namely 1-ethyl-3-methylimidazolium difluoro(oxalate)borate (EMImDFOB) was synthesized by metathesis reaction between 1-ethyl-3-methylimiazolium bromide and lithium difluoro(oxalate)borate (LiDFOB). Ternary gel polymer electrolyte membranes were prepared using electrolyte mixture EMImDFOB/LiDFOB with poly vinylidenefluoride-co-hexafluoropropylene (PVdF-co-HFP) as a host matrix by facile solvent-casting method and plausibly demonstrated its feasibility to use in lithium ion batteries. Amongst ternary gel electrolyte membrane, DFOB-GPE3, which contained 80 wt% of EMImDFOB/LiDFOB and 20 wt% PVdF-co-HFP, showed excellent electrochemical and cycling behaviors. The highest ionic conductivity was found to be 10⁻³ Scm⁻¹ at 378 K. Charge-discharge profile of Li/DFOB-GPE3/LiCoO₂ coin cell displayed a maximum discharge capacity of 148.4 mAhg⁻¹ at C/10 rate with impressive capacity retention capability and columbic efficiency at 298 K.

Bioinspired integrated nanosystems based on solid-state nanopores: "iontronic" transduction of biological, chemical and physical stimuli

The ability of living systems to respond to stimuli and process information has encouraged scientists to develop integrated nanosystems displaying similar functions and capabilities. In this regard, biological pores have been a source of inspiration due to their exquisite control over the transport of ions within cells, a feature that ultimately plays a major role in multiple physiological processes, e.g. transduction of physical stimuli into nervous signals. Developing abiotic nanopores, which respond to certain chemical, biological or physical inputs producing "iontronic" signals, is now a reality thanks to the combination of "soft" surface science with nanofabrication techniques. The interplay between the functional richness of predesigned molecular components and the remarkable physical characteristics of nanopores plays a critical role in the rational integration of molecular functions into nanopore environments, permitting us to envisage nanopore-based biomimetic integrated nanosystems that respond to a variety of external stimuli such as pH, redox potential, molecule concentration, temperature, or light. Transduction of these stimuli into a predefined "iontronic" response can be amplified by exploiting nanoconfinement and physico-chemical effects such as charge distribution, steric constraints, equilibria displacement, or local changes in ionic concentration, to name but a few examples. While in past decades the focus has been mostly on their fundamental aspects and the in-depth study of their interesting transport properties, for several years now nanopore research has started to shift towards specific practical applications. This work is dedicated to bringing together the latest developments in the use of nanopores as "iontronic" transducing elements. Our aim is to show the wide potential of abiotic nanopores in sensing and signal transduction and also to promote the potential of this technology among doctoral students, postdocs, and researchers. We believe that even a casual reader of this perspective will not fail to be impressed by the wealth of opportunities that solid-state nanopores can offer to the transduction of biological, physical and chemical stimuli.

Controlled radical polymerization of vinyl ketones using visible light

Herein we report the photoinduced electron transfer–reversible addition–fragmentation chain transfer (PET-RAFT) polymerization of a range of vinyl ketone monomers including methyl, ethyl and phenyl derivatives, using Eosin Y as an organic photoredox catalyst and visible light.

Microsupercapacitors as miniaturized energy-storage components for on-chip electronics

The push towards miniaturized electronics calls for the development of miniaturized energy-storage components that can enable sustained, autonomous operation of electronic devices for applications such as wearable gadgets and wireless sensor networks. Microsupercapacitors have been targeted as a viable route for this purpose, because, though storing less energy than microbatteries, they can be charged and discharged much more rapidly and have an almost unlimited lifetime. In this Review, we discuss the progress and the prospects of integrated miniaturized supercapacitors. In particular, we discuss their power performances and emphasize the need of a three-dimensional design to boost their energy-storage capacity. This is obtainable, for example, through self-supported nanostructured electrodes. We also critically evaluate the performance metrics currently used in the literature to characterize microsupercapacitors and offer general guidelines to benchmark performances towards prospective applications.

Energy Harvesters for Wearable and Stretchable Electronics: From Flexibility to Stretchability

The rapid advancements of wearable electronics have caused a paradigm shift in consumer electronics, and the emerging development of stretchable electronics opens a new spectrum of applications for electronic systems. Playing a critical role as the power sources for independent electronic systems, energy harvesters with high flexibility or stretchability have been the focus of research efforts over the past decade. A large number of the flexible energy harvesters developed can only operate at very low strain level (≈0.1%), and their limited flexibility impedes their application in wearable or stretchable electronics. Here, the development of highly flexible and stretchable (stretchability >15% strain) energy harvesters is reviewed with emphasis on strategies of materials synthesis, device fabrication, and integration schemes for enhanced flexibility and stretchability. Due to their particular potential applications in wearable and stretchable electronics, energy-harvesting devices based on piezoelectricity, triboelectricity, thermoelectricity, and dielectric elastomers have been largely developed and the progress is summarized. The challenges and opportunities of assembly and integration of energy harvesters into stretchable systems are also discussed.

Applications of large-scale density functional theory in biology

Density functional theory (DFT) has become a routine tool for the computation of electronic structure in the physics, materials and chemistry fields. Yet the application of traditional DFT to problems in the biological sciences is hindered, to a large extent, by the unfavourable scaling of the computational effort with system size. Here, we review some of the major software and functionality advances that enable insightful electronic structure calculations to be performed on systems comprising many thousands of atoms. We describe some of the early applications of large-scale DFT to the computation of the electronic properties and structure of biomolecules, as well as to paradigmatic problems in enzymology, metalloproteins, photosynthesis and computer-aided drug design. With this review, we hope to demonstrate that first principles modelling of biological structure-function relationships are approaching a reality.

How Did the Tree of Knowledge Get Its Blossom? The Rise of Physical and Theoretical Chemistry, with an Eye on Berlin and Leipzig

"Physical chemistry is not just a branch on but the blossom of the tree of knowledge," declared Ostwald, a most vocal advocate of his field, conceived as the basis for all of chemistry. This Essay describes the historical development of physical and theoretical chemistry with a focus on Berlin and Leipzig, its foremost centers in Germany.

Three-dimensional printed knotted reactors enabling highly sensitive differentiation of silver nanoparticles and ions in aqueous environmental samples

Whether silver nanoparticles (AgNPs) persist or release silver ions (Ag(+)) when discharged into a natural environment has remained an unresolved issue. In this study, we employed a low-cost stereolithographic three-dimensional printing (3DP) technology to fabricate the angle-defined knotted reactors (KRs) to construct a simple differentiation scheme for quantitative assessment of Ag(+) ions and AgNPs in municipal wastewater samples. We chose xanthan/phosphate-buffered saline as a dispersion medium for in situ stabilization of the two silver species, while also facilitating their extraction from complicated wastewater matrices. After method optimization, we measured extraction efficiencies of 54.5 and 32.3% for retaining Ag(+) ions and AgNPs, respectively, in the printed KR (768-turn), with detection limits (DLs) of 0.86 and 0.52 ng L(-1) when determining Ag(+) ions and AgNPs, respectively (sample run at pH 11 without a rinse solution), and 0.86 ng L(-1) when determining Ag(+) ions alone (sample run at pH 12 with a 1.5-mL rinse solution). The proposed scheme is tolerant of the wastewater matrix and provides more reliable differentiation between Ag(+)/AgNPs than does a conventional filtration method. The concept and applicability of adopting 3DP technology to renew traditional KR devices were evidently proven by means of these significantly improved analytical performance. Our analytical data suggested that the concentrations of Ag(+) ions and AgNPs in the tested industrial wastewater sample were both higher than those in domestic wastewater, implying that industrial activity might be a main source of environmental silver species, rather than domestic discharge from AgNP-containing products.

Engineering the surface of rutile TiO2 nanoparticles with quantum pits towards excellent lithium storage

Unique rutile TiO₂ nanoparticles with quantum pits have been successfully synthesized by a facile solution and subsequent thermal annealing method. The resultant rutile TiO₂ nanoparticles exhibit excellent lithium storage properties.

Co9S8 nanoparticles encapsulated in nitrogen-doped mesoporous carbon networks with improved lithium storage properties

Co₉S₈ nanoparticles encapsulated in nitrogen-doped mesoporous carbon networks have been synthesized by annealing a cobalt containing metal organic framework with sulfur powders. The products exhibit excellent lithium storage properties.

A structure/catalytic activity study of gold(i)–NHC complexes, as well as their recyclability and reusability, in the hydration of alkynes in aqueous medium

Comparative studies were carried out with the addition of different silver salts. Our results indicate that the bulkier complex is the most effective and that the addition of methanol as co-solvent not only shortens reaction times but also stabilizes the less bulky complexes.

Transmutation of Personal Glucose Meters into Portable and Highly Sensitive Microbial Pathogen Detection Platform

Herein, for the first time, we presented a simple and general approach by using personal glucose meters (PGM) for portable and ultrasensitive detection of microbial pathogens. Upon addition of pathogenic bacteria, glucoamylase-quaternized magnetic nanoparticles (GA-QMNPS) conjugates were disrupted by the competitive multivalent interactions between bacteria and QMNPS, resulting in the release of GA. After magnetic separation, the free GA could catalyze the hydrolysis of amylose into glucose for quantitative readout by PGM. In such way, PGM was transmuted into a bacterial detection device and extremely low detection limits down to 20 cells mL(-1) was achieved. More importantly, QMNPS could inhibit the growth of the bacteria and destroy its cellular structure, which enabled bacteria detection and inhibition simultaneously. The simplicity, portability, sensitivity and low cost of presented work make it attractive for clinical applications.

Interface-Free Area-Scalable Self-Powered Electroluminescent System Driven by Triboelectric Generator

Self-powered system that is interface-free is greatly desired for area-scalable application. Here we report a self-powered electroluminescent system that consists of a triboelectric generator (TEG) and a thin-film electroluminescent (TFEL) lamp. The TEG provides high-voltage alternating electric output, which fits in well with the needs of the TFEL lamp. Induced charges pumped onto the lamp by the TEG generate an electric field that is sufficient to excite luminescence without an electrical interface circuit. Through rational serial connection of multiple TFEL lamps, effective and area-scalable luminescence is realized. It is demonstrated that multiple types of TEGs are applicable to the self-powered system, indicating that the system can make use of diverse mechanical sources and thus has potentially broad applications in illumination, display, entertainment, indication, surveillance and many others.

Reserving Interior Void Space for Volume Change Accommodation: An Example of Cable-Like MWNTs@SnO2@C Composite for Superior Lithium and Sodium Storage

Reserving interior void space in the cable-like structure of multiwalled carbon nanotubes-in-SnO2-in-carbon layer (MWNTs@SnO2@C) is reported for the first time. Such a design enables the structure performing excellent for Li and Na storage, which benefit from the good electrical conductivity of MWNTs and carbon layer as well as the reserved void space to accommodate the volume changes of SnO2.

Triboelectric charging sequence induced by surface functionalization as a method to fabricate high performance triboelectric generators

Two different materials, apart from each other in a triboelectric series, are required to fabricate high performance triboelectric generators (TEGs). Thus, it often limits the choices of materials and causes related processing issues for TEGs. To address this issue, we report a simple surface functionalization method that can effectively change the triboelectric charging sequence of the materials, broadening material choices and enhancing the performance of TEGs. Specifically, we functionalized the surfaces of the polyethylene terephthalate (PET) films either with poly-l-lysine solution or trichloro(1H,1H,2H,2H-perfluorooctyl) silane (FOTS). Consequently, the PET surfaces were modified to have different triboelectric polarities in a triboelectric series. The TEGs, fabricated using this approach, demonstrated the maximum Vopen-circuit (Voc) of ∼330 V and Jshort-circuit (Jsc) of ∼270 mA/m(2), respectively, at an applied force of 0.5 MPa. Furthermore, the functionalized surfaces of TEGs demonstrated superior stability during cyclic measurement over 7200 cycles, maintaining the performance even after a month. The approach introduced here is a simple, effective, and cost-competitive way to fabricate TEGs, which can also be easily adopted for various surface patterns and device structures.