Self-Assembly of Hybrid Nanorods for Enhanced Volumetric Performance of Nanoparticles in Li-Ion Batteries

The benefits of nanosize active particles in Li-ion batteries are currently ambiguous. They are acclaimed for enhancing the cyclability of certain electrode materials and for improving rate performance. However, at the same time, nanoparticles are criticized for causing side reactions as well as for their low packing density and, therefore, poor volumetric battery performance. This paper demonstrates for the first time that self-assembly can be used to pack nanoparticles into dense battery electrodes with up to 4-fold higher volumetric capacities. Furthermore, despite the dense packing of the self-assembled electrodes, they retain a higher volumetric capacity than randomly dispersed nanoparticles up to rates of 5 C. Finally, we did not observe substential degradation in capacity after 1000 cycles, and post-mortem analysis indicates that the self-assembled structures are maintained during cycling. Therefore, the proposed self-assembled electrodes profit from the advantages of nanostructured battery materials without compromising the volumetric performance.

Antimony Nanorod Encapsulated in Cross-Linked Carbon for High-Performance Sodium Ion Battery Anodes

Antimony- (Sb) based materials have been considered as one of promising anodes for sodium ion batteries (SIBs) owing to their high theoretical capacities and appropriate sodium inserting potentials. So far, the reported energy density and cycling stability of the Sb-based anodes for SIBs are quite limited and need to be significantly improved. Here, we develop a novel Sb/C hybrid encapsulating the Sb nanorods into highly conductive N and S codoped carbon (Sb@(N, S-C)) frameworks. As an anode for SIBs, the Sb@(N, S-C) hybrid maintains high reversible capacities of 621.1 mAh g^-1 at 100 mA g^-1 after 150 cycles, and 390.8 mAh g^-1 at 1 A g^-1 after 1000 cycles. At higher current densities of 2, 5, and 10 A g^-1, the Sb@(N, S-C) hybrid also can display high reversible capacities of 534.4, 430.8, and 374.7 mAh g^-1, respectively. Such impressive sodium storage properties are mainly attributed to the unique cross-linked carbon networks providing highly conductive frameworks for fast transfer of ions and electrons, alleviating the volume expansion and preventing the agglomeration of Sb nanorods during the cycling.

Physical-Chemical Properties of Biogenic Selenium Nanostructures Produced by Stenotrophomonas maltophilia SeITE02 and Ochrobactrum sp. MPV1

Stenotrophomonas maltophilia SeITE02 and Ochrobactrum sp. MPV1 were isolated from the rhizosphere soil of the selenium-hyperaccumulator legume Astragalus bisulcatus and waste material from a dumping site for roasted pyrites, respectively. Here, these bacterial strains were studied as cell factories to generate selenium-nanostructures (SeNS) under metabolically controlled growth conditions. Thus, a defined medium (DM) containing either glucose or pyruvate as carbon and energy source along with selenite () was tested to evaluate bacterial growth, oxyanion bioconversion and changes occurring in SeNS features with respect to those generated by these strains grown on rich media. Transmission electron microscopy (TEM) images show extra- or intra-cellular emergence of SeNS in SeITE02 or MPV1 respectively, revealing the presence of two distinct biological routes of SeNS biogenesis. Indeed, the stress exerted by upon SeITE02 cells triggered the production of membrane vesicles (MVs), which surrounded Se-nanoparticles (SeNPs_{SeITE02-G_e} and SeNPs_{SeITE02-P_e} with average diameter of 179 ± 56 and 208 ± 60 nm, respectively), as highlighted by TEM and scanning electron microscopy (SEM), strongly suggesting that MVs might play a crucial role in the excreting mechanism of the SeNPs in the extracellular environment. On the other hand, MPV1 strain biosynthesized intracellular inclusions likely containing hydrophobic storage compounds and SeNPs (123 ± 32 nm) under pyruvate conditioning, while the growth on glucose as the only source of carbon and energy led to the production of a mixed population of intracellular SeNPs (118 ± 36 nm) and nanorods (SeNRs; average length of 324 ± 89). SEM, fluorescence spectroscopy, and confocal laser scanning microscopy (CLSM) revealed that the biogenic SeNS were enclosed in an organic material containing proteins and amphiphilic molecules, possibly responsible for the high thermodynamic stability of these nanomaterials. Finally, the biogenic SeNS extracts were photoluminescent upon excitation ranging from 380 to 530 nm, whose degree of fluorescence emission (λ_em = 416–640 nm) was comparable to that from chemically synthesized SeNPs with L-cysteine (L-cys SeNPs). This study offers novel insights into the formation, localization, and release of biogenic SeNS generated by two different Gram-negative bacterial strains under aerobic and metabolically controlled growth conditions. The work strengthens the possibility of using these bacterial isolates as eco-friendly biocatalysts to produce high quality SeNS targeted to possible biomedical applications and other biotechnological purposes.

Electron-Hole Correlations Govern Auger Recombination in Nanostructures

The fast nonradiative decay of multiexcitonic states via Auger recombination is a fundamental process affecting a variety of applications based on semiconductor nanostructures. From a theoretical perspective, the description of Auger recombination in confined semiconductor nanostructures is a challenging task due to the large number of valence electrons and exponentially growing number of excited excitonic and biexcitonic states that are coupled by the Coulomb interaction. These challenges have restricted the treatment of Auger recombination to simple, noninteracting electron-hole models. Herein we present a novel approach for calculating Auger recombination lifetimes in confined nanostructures having thousands to tens of thousands of electrons, explicitly including electron-hole interactions. We demonstrate that the inclusion of electron-hole correlations are imperative to capture the correct scaling of the Auger recombination lifetime with the size and shape of the nanostructure. In addition, correlation effects are required to obtain quantitatively accurate lifetimes even for systems smaller than the exciton Bohr radius. Neglecting such correlations can result in lifetimes that are two orders of magnitude too long. We establish the utility of the new approach for CdSe quantum dots of varying sizes and for CdSe nanorods of varying diameters and lengths. Our new approach is the first theoretical method to postdict the experimentally known "universal volume scaling law" for quantum dots and makes novel predictions for the scaling of the Auger recombination lifetimes in nanorods.

Evaluation of gold nanorods toxicity on isolated mitochondria

Gold nanorods (AuNRs) have been studied extensively in biomedicine due to their biocompatibility and their unique properties. Some studies reported that AuNRs selectively accumulate on cancer cell mitochondria causing its death. However, the immediate effects of this accumulation needed further investigations. In this context, we evaluated the effect of AuNRs on the mitochondrial integrity of isolated rat liver mitochondria. We verified that AuNRs decreased the mitochondrial respiratory ratio by decreasing the phosphorylation and maximal states. Additionally, AuNRs caused a decrease in the production of mitochondrial ROS and a delay in mitochondrial swelling. Moreover, even with cyclosporine A treatment, AuNRs disrupted the mitochondrial potential. With the highest concentration of AuNRs studied, disorganized mitochondrial crests and intermembrane separation were observed in TEM images. These results indicate that AuNRs can interact with mitochondria, disrupting the electron transport chain. This study provides new evidence of the immediate effects of AuNRs on mitochondrial bioenergetics.

Cascade Amplifiers of Intracellular Reactive Oxygen Species Based on Mitochondria-Targeted Core-Shell ZnO-TPP@D/H Nanorods for Breast Cancer Therapy

Tumor cells are vulnerable to reactive oxygen species (ROS). However, it is still a challenge to induce ROS efficiently in tumor cells. In this study, cascade amplifiers of intracellular ROS based on charge-reversible mitochondria-targeted ZnO-TPP@D/H nanorods (NRs) were first developed for breast cancer therapy. The core-shell ZnO-TPP@D/H NR with a particle size of 179.60 ± 5.67 nm was composed of a core of a ZnO NR, an inner shell of triphenyl phosphonium (TPP), and an outer shell of heparin. Doxorubicin (DOX) was loaded on ZnO-TPP@D/H NRs with high drug loading efficiency of 22.00 ± 0.18%. The zeta potential of ZnO-TPP@D/H NRs varied from 24.00 ± 0.83 to -34.06 ± 0.87 mV after heparin coating, protecting ZnO-TPP@D/H NRs from nonspecific adsorption in circulation. Mitochondrial targeting was achieved after the degradation of heparin. Cellular uptake assays showed that ZnO-TPP@D/H NRs could accumulate in mitochondria. ROS generation assays showed that ZnO-TPP@D/H NRs could triple the intracellular ROS in 4T1 cells (highly metastatic breast cancer cells) than free DOX. Western blot demonstrated that ZnO-TPP@D/H NRs dramatically induced cell apoptosis in 4T1 cells. In vivo experiments suggested the antitumor potential of ZnO-TPP@D/H NRs.

Anti-Candidal Activity and In Vitro Cytotoxicity Assessment of Graphene Nanoplatelets Decorated with Zinc Oxide Nanorods

Candida albicans is the most common pathogenic fungus that is isolated in nosocomial infections in medically and immune-compromised patients. The ability of C. albicans to convert its form from yeast to hyphal morphology contributes to biofilm development that effectively shelters Candida against the action of antifungals molecules. In the last years, nanocomposites are the most promising solutions against drug-resistant microorganisms. The aim of this study was to investigate the antifungal activity of graphene nanoplateles decorated with zinc oxide nanorods (ZNGs) against the human pathogen Candida albicans. We observed that ZNGs were able to induce a significant mortality in fungal cells, as well as to affect the main virulence factors of this fungus or rather the hyphal development and biofilm formation. Reactive Oxygen Species (ROS) formation in yeast cells resulted one of the mechanisms of ZNGs to induce mortality. Finally, the toxicity of this nanomaterial was tested also on human keratinocyte cell line HaCaT. Our data indicated that ZNGs resulted not toxic when their aggregation state decreased by adding glycerol as emulsifier to ZNGs suspensions or when HaCaT cells were grown on ZNGs-coated glasses. Overall, the results that were obtained indicated that ZNGs could be exploited as an antifungal nanomaterial with a high degree of biocompatibility on human cells.

Rod-shaped mesoporous silica nanoparticles for nanomedicine: recent progress and perspectives

INTRODUCTION

Interest in mesoporous silica nanoparticles for drug delivery has resulted in a good understanding of the impact of size and surface chemistry of these nanoparticles on their performance as drug carriers. Shape has emerged as an additional factor that can have a significant effect on delivery efficacy. Rod-shaped mesoporous silica nanoparticles show improvements in drug delivery relative to spherical mesoporous silica nanoparticles.

AREAS COVERED

This review summarises the synthesis methods for producing rod-shaped mesoporous silica nanoparticles for use in nanomedicine. The second part covers recent progress of mesoporous silica nanorods by comparing the impact of sphere and rod-shape on drug delivery efficiency.

EXPERT OPINION

As hollow mesoporous silica nanorods are capable of higher drug loads than most other drug delivery vehicles, such particles will reduce the amount of mesoporous silica in the body for efficient therapy. However, the importance of nanoparticle shape on drug delivery efficiency is not well understood for mesoporous silica. Studies that visualize and quantify the uptake pathway of mesoporous silica nanorods in specific cell types and compare the cellular uptake to the well-studied nanospheres should be the focus of research to better understand the role of shape in uptake.

One-Step Acidic Hydrothermal Preparation of Dendritic Rutile TiO₂ Nanorods for Photocatalytic Performance

Three-dimensional and dendritic rutile TiO₂ nanorods were successfully fabricated on a Ti foil surface using a one-step acidic hydrothermal method. The TiO₂ nanorods were characterized using X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and optical contact angle testing. The results showed that the nanorods with diameters of 100⁻500 nm and lengths of 100 nm to 1 μm were obtained on the Ti foil surface. The length and density of the TiO₂ nanorods were perfect at the conditions of HCl concentration 0.5 mol/L, temperature 220 °C, and reaction time 12 h. The TiO₂ nanorods formed parallel to the consumption of Ti and grew along the (110) direction having a tetragonal rutile crystal. The morphology of the nanorods possessed a three-dimensional structure. The contact angle of the nanorods was only 13 ± 3.1°. Meanwhile, the photocatalytic activities of the TiO₂ nanorods were carried out using ultraviolet fluorescence spectrophotometry for the methyl orange detection, and the degradation was found to be about 71.00% ± 2.43%. Thus, TiO₂ nanorods can be developed by a one-step acidic hydrothermal method using Ti foil simultaneously as the substrate with a TiO₂ source; the TiO₂ nanorods exhibited photocatalytic performance while being environment-friendly.

Polarization-Selecting III-Nitride Elliptical Nanorod Light-Emitting Diodes Fabricated with Nanospherical-Lens Lithography

Current-injected elliptical nanorod light-emitting diodes (LEDs) are demonstrated to emit polarized light with a bottom-emitting configuration. The polarization ratio of the electroluminescence reaches 3.17 when the length of the minor axis for the elliptical nanorods is as small as 150 nm. Electromagnetic simulation confirms the occurrence of the polarization selectivity especially when the length of the minor axis is down to 150 nm. Light with different polarization travels at different speeds in these asymmetric elliptical nanorods. Only one polarization experiences destructive interference between the light directly from the source and the reflected light by the top metal interface. A thin light-blocking layer is incorporated to increase the polarization selectivity. It is also not recommended to infill the gap with SiO₂ since the polarization selectivity will be reduced. The proposed nanorod LEDs are fabricated using top-down nanofabrication approaches by combining nanospherical-lens lithography and two-step etch processes, which are both fully compatible with current semiconductor manufacturing processes. Results in this study will help to develop a chip-level polarization-selecting LED, which will be very useful for applications that require polarized light. It is especially beneficial for applications that are not suitable for using an external polarizer or require polarized light at the individual chip level.

High-Aspect Ratio β-Ga₂O₃ Nanorods via Hydrothermal Synthesis

High-aspect ratio β-Ga₂O₃ nanorods consisting of prism-like crystals were formed using gallium oxyhydroxide and ammonia hydroxide via a hydrothermal synthesis followed by the subsequent calcination process. The formation of high-aspect ratio β-Ga₂O₃ nanorods was attributed to the oriented attachment mechanism that was present during the hydrothermal synthesis. A field-effect transistor was fabricated using the high-aspect ratio β-Ga₂O₃ nanorod, and it exhibited the typical charge transfer properties of an n-type semiconductor. This facile approach to forming high-aspect ratio nanorods without any surfactants or additives can broaden the science of β-Ga₂O₃ and expedite the integration of one-dimensional β-Ga₂O₃ into future electronics, sensors, and optoelectronics.

Laser-Ablated ZnO Nanoparticles and Their Photocatalytic Activity toward Organic Pollutants

This work aimed to prepare nanostructures of ZnO with various lasers, testing them as photocatalysts, and comparing their morphology and activity in the degradation of organic pollutants in aqueous media. ZnO nanospheres (ns-ZnO) and ZnO nanorods (ms-ZnO) were prepared via the laser ablation of a Zn metal plate in water using nanosecond- and millisecond-pulsed lasers, respectively. The obtained materials were characterized using a set of optical, structural, and surface-science techniques, such as UV-vis spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Under visible-light irradiation, both nanostructures were found to be catalytically active toward the oxidation of methylene blue, which was used as a model compound. The ZnO nanorods fabricated with the millisecond laser showed better photocatalytic performance than their spherically shaped counterparts obtained by means of the nanosecond laser, which could be assigned to a larger number of defects on the ms-ZnO surface.

Charge and Bonding in CuGeO3 Nanorods

We combine infrared and Raman spectroscopies to investigate finite length scale effects in CuGeO₃ nanorods. The infrared-active phonons display remarkably strong size dependence whereas the Raman-active features are, by comparison, nearly rigid. A splitting analysis of the Davydov pairs reveals complex changes in chemical bonding with rod length and temperature. Near the spin-Peierls transition, stronger intralayer bonding in the smallest rods indicates a more rigid lattice which helps to suppress the spin-Peierls transition. Taken together, these findings advance the understanding of size effects and collective phase transitions in low-dimensional oxides.

Coordinating Self-Assembly of Copper Perylenetetracarboxylate Nanorods: Selectively Lighting up Normal Cells around Cancerous Ones for Better Cancer Diagnosis

Specific imaging of cancer cells has been well-accepted in cancer diagnosis although it cannot precisely mark the boundary between the normal and cancerous cells and report their mutual influence. We report a nanorod fluorescent probe of copper perylenetetracarbonate (PTC-Cu) that can specifically light up normal cells. In combination with cancer cell imaging, the cocultured normal and cancer cells can be lit up with different colors, offering a clear contrast between the normal and cancer cells when they coexist. Because cancerous cells are only 20-30% in cancer area, this provides a possibility to visibly detect the mutual influence between the cancer and normal cells during therapy. We expect this method is beneficial to better cancer diagnosis and therapy.

Special Issue: Zinc Oxide Nanostructures: Synthesis and Characterization

Zinc oxide (ZnO) is a wide band gap semiconductor with an energy gap of 3.37 eV at room temperature. It has been used considerably for its catalytic, electrical, optoelectronic, and photochemical properties. ZnO nanomaterials, such as quantum dots, nanorods, and nanowires, have been intensively investigated for their important properties. Many methods have been described in the literature for the production of ZnO nanostructures, such as laser ablation, hydrothermal methods, electrochemical deposition, sol⁻gel methods, Chemical Vapour Deposition, molecular beam epitaxy, the common thermal evaporation method, and the soft chemical solution method. The present Special Issue is devoted to the Synthesis and Characterization of ZnO nanostructures with novel technological applications.

Effect of Temperature and Growth Time on Vertically Aligned ZnO Nanorods by Simplified Hydrothermal Technique for Photoelectrochemical Cells

Despite its large band gap, ZnO has wide applicability in many fields ranging from gas sensors to solar cells. ZnO was chosen over other materials because of its large exciton binding energy (60 meV) and its stability to high-energy radiation. In this study, ZnO nanorods were deposited on ITO glass via a simple dip coating followed by a hydrothermal growth. The morphological, structural and compositional characteristics of the prepared films were analyzed using X-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM), and ultraviolet-visible spectroscopy (UV-Vis). Photoelectrochemical conversion efficiencies were evaluated via photocurrent measurements under calibrated halogen lamp illumination. Thin film prepared at 120 °C for 4 h of hydrothermal treatment possessed a hexagonal wurtzite structure with the crystallite size of 19.2 nm. The average diameter of the ZnO nanorods was 37.7 nm and the thickness was found to be 2680.2 nm. According to FESEM images, as the hydrothermal growth temperature increases, the nanorod diameter become smaller. Moreover, the thickness of the nanorods increase with the growth time. Therefore, the sample prepared at 120 °C for 4 h displayed an impressive photoresponse by achieving high current density of 0.1944 mA/cm².

Comparative analysis of the toxicity of gold nanoparticles in zebrafish

The use of nanoparticles - particles that range in size from 1 to 100 nm - has become increasingly prevalent in recent years, bringing with it a variety of potential toxic effects. Zebrafish embryos were exposed during the 3 day postfertilization period to gold nanospheres (GNSs), gold nanorods (GNRs), GNRs coated with polystyrene sulphate (PSS-GNRs) and GNRs coated with both PSS and polyallamine hydrochloride (PAH-PSS-GNRs). All nanorods were stabilized with cetyltrimethylammonium bromide. GNSs were the least toxic of the nanoparticles studied, with exposure resulting in no significant changes in mortality, hatching or heart rate. Exposure to GNRs and PSS-GNRs resulted in significant increases in mortality and significant decreases in hatching and heart rate. Treatment with GNRs caused significant changes in the expression of a variety of oxidative stress genes. The toxic effects of GNRs were ameliorated by coating them with PSS and, to a more marked extent, with a double coating of PSS and polyallamine hydrochloride.

Effects of N₂ Partial Pressure on Growth, Structure, and Optical Properties of GaN Nanorods Deposited by Liquid-Target Reactive Magnetron Sputter Epitaxy

GaN nanorods, essentially free from crystal defects and exhibiting very sharp band-edge luminescence, have been grown by reactive direct-current magnetron sputter epitaxy onto Si (111) substrates at a low working pressure of 5 mTorr. Upon diluting the reactive N₂ working gas with a small amount of Ar (0.5 mTorr), we observed an increase in the nanorod aspect ratio from 8 to ~35, a decrease in the average diameter from 74 to 35 nm, and a two-fold increase in nanorod density. With further dilution (Ar = 2.5 mTorr), the aspect ratio decreased to 14, while the diameter increased to 60 nm and the nanorod density increased to a maximum of 2.4 × 10⁹ cm⁻². Yet, lower N₂ partial pressures eventually led to the growth of continuous GaN films. The observed morphological dependence on N₂ partial pressure is explained by a change from N-rich to Ga-rich growth conditions, combined with reduced GaN-poisoning of the Ga-target as the N₂ gas pressure is reduced. Nanorods grown at 2.5 mTorr N₂ partial pressure exhibited a high intensity 4 K photoluminescence neutral donor bound exciton transitions (D⁰X_A) peak at ~3.479 eV with a full-width-at-half-maximum of 1.7 meV. High-resolution transmission electron microscopy corroborated the excellent crystalline quality of the nanorods.

Microstructure and optical properties of ZnO nanorods prepared by anodic arc plasma method

INTRODUCTION

A one-dimensional ZnO nanostructure is a versatile and multifunctional n-type semiconductor. In this paper, ZnO nanorods were successfully prepared by the anodic arc plasma method in an oxidizing atmosphere.

METHODS

The composition, morphology, crystal microstructure, and optical properties of ZnO nanorods were characterized by using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and the corresponding selected-area electron diffraction (SAED), X-ray energy dispersive spectrometry (XEDS), ultraviolet-visible (UV-VIS) spectroscopy, Raman scattering spectrum (Raman), and photoluminescence spectrum (PL).

RESULTS

The experiment results show that ZnO nanorods synthesized by this method possess hexagonal wurtzite crystal structure with good crystallization, no other impurity phases are observed, the crystalline size is about 18 nm, and the lattice constant distortion occurs compared to that of bulk ZnO. The morphology of the sample is a rod-like shape, the length ranges from 100 nm to 300 nm, the average diameter is approximately 20 nm, and the aspect ratio is relatively high. The UV-VIS absorption spectrum occurs red shift, The Raman spectrum further demonstrates that the major peaks are assigned to ZnO optical vibrational modes, and the PL spectrum exhibits coexistence properties of ultraviolet (UV) and green emission.

CONCLUSIONS

The results prove that ZnO nanorods with hexagonal wurtzite crystal structure were successfully prepared by the anodic arc plasma method in an oxidizing atmosphere.

Dual Effects of Nanostructuring and Oxygen Vacancy on Photoelectrochemical Water Oxidation Activity of Superstructured and Defective Hematite Nanorods

An Ar atmospheric treatment is rationally used to etch and activate hematite nanoflakes (NFs) as photoanodes toward enhanced photoelectrochemical water oxidation. The formation of a highly ordered hematite nanorods (NRs) array containing a high density of oxygen vacancy is successfully prepared through in situ reduction of NFs in Ar atmosphere. Furthermore, a hematite (104) plane and an iron suboxide layer at the absorber/back-contact interface are formed. The material defects produced by a thermal oxidation method can be critical for the morphology transformation from 2D NFs to 1D NRs. The resulting hematite NR photoanodes show high efficiency toward solar water splitting with improved light harvesting capabilities, leading to an enhanced photoresponse due to the artificially formed oxygen vacancies.

Soluble Molecularly Imprinted Nanorods for Homogeneous Molecular Recognition

Nowadays, it is still difficult for molecularly imprinted polymers (MIPs) to achieve homogeneous recognition since they cannot be easily dissolved in organic or aqueous phase. To address this issue, soluble molecularly imprinted nanorods have been synthesized by using soluble polyaniline doped with a functionalized organic protonic acid as the polymer matrix. By employing 1-naphthoic acid as a model, the proposed imprinted nanorods exhibit an excellent solubility and good homogeneous recognition ability. The imprinting factor for the soluble imprinted nanoroads is 6.8. The equilibrium dissociation constant and the apparent maximum number of the proposed imprinted nanorods are 248.5 μM and 22.1 μmol/g, respectively. We believe that such imprinted nanorods may provide an appealing substitute for natural receptors in homogeneous recognition related fields.

Superior Photodetectors Based on All-Inorganic Perovskite CsPbI3 Nanorods with Ultrafast Response and High Stability

Currently, one-dimensional all-inorganic CsPbX₃ (X = Br, Cl, and I) perovskites have attracted great attention, owning to their promising and exciting applications in optoelectronic devices. Herein, we reported the exploration of superior photodetectors (PDs) based on a single CsPbI₃ nanorod. The as-constructed PDs had a totally excellent performance with a responsivity of 2.92 × 10³ A·W^-1 and an ultrafast response time of 0.05 ms, respectively, which were both comparable to the best ones ever reported for all-inorganic perovskite PDs. Furthermore, the detectivity of the PDs approached up to 5.17 × 10¹³ Jones, which was more than 5 times the best one ever reported. More importantly, the as-constructed PDs showed a high stability when maintained under ambient conditions.

One-Step Synthesis of Co-Doped In2O3 Nanorods for High Response of Formaldehyde Sensor at Low Temperature

Uniform and monodisperse Co-doped In₂O₃ nanorods were fabricated by a facile and environmentally friendly hydrothermal strategy that combined the subsequent annealing process, and their morphology, structure, and formaldehyde (HCHO) gas sensing performance were investigated systematically. Both pure and Co-doped In₂O₃ nanorods had a high specific surface area, which could offer abundant reaction sites to gas molecular diffusion and improve the response of the gas sensor. Results revealed that the In₂O₃/1%Co nanorods exhibited a higher response of 23.2 for 10 ppm of HCHO than that of the pure In₂O₃ nanorods by 4.5 times at 130 °C. More importantly, the In₂O₃/1%Co nanorods also presented outstanding selectivity and long-term stability. The superior gas sensing properties were mainly attributed to the incorporation of Co, which suggested the important role of the amount of oxygen vacancies and adsorbed oxygen in enhancing HCHO sensing performance of In₂O₃ sensors.

Achieving the Widest Range of Syngas Proportions at High Current Density over Cadmium Sulfoselenide Nanorods in CO2 Electroreduction

Electroreduction of CO₂ is a sustainable approach to produce syngas with controllable ratios, which are required as specific reactants for the optimization of different industrial processes. However, it is challenging to achieve tunable syngas production with a wide ratio of CO/H₂ , while maintaining a high current density. Herein, cadmium sulfoselenide (CdS_x Se_1-x ) alloyed nanorods are developed, which enable the widest range of syngas proportions ever reported at the current density above 10 mA cm^-2 in CO₂ electroreduction. Among CdS_x Se_1-x nanorods, CdS nanorods exhibit the highest Faradaic efficiency (FE) of 81% for CO production with a current density of 27.1 mA cm^-2 at -1.2 V vs. reversible hydrogen electrode. With the increase of Se content in CdS_x Se_1-x nanorods, the FE for H₂ production increases. At -1.2 V vs. RHE, the ratios of CO/H₂ in products vary from 4:1 to 1:4 on CdS_x Se_1-x nanorods (x from 1 to 0). Notably, all proportions of syngas are achieved with current density higher than ≈25 mA cm^-2 . Mechanistic study reveals that the increased Se content in CdS_x Se_1-x nanorods strengthens the binding of H atoms, resulting in the increased coverage of H* and thus the enhanced selectivity for H₂ production in CO₂ electroreduction.

Single-Cell Analysis Using Hyperspectral Imaging Modalities

Almost a decade ago, hyperspectral imaging (HSI) was employed by the NASA in satellite imaging applications such as remote sensing technology. This technology has since been extensively used in the exploration of minerals, agricultural purposes, water resources, and urban development needs. Due to recent advancements in optical re-construction and imaging, HSI can now be applied down to micro- and nanometer scales possibly allowing for exquisite control and analysis of single cell to complex biological systems. This short review provides a description of the working principle of the HSI technology and how HSI can be used to assist, substitute, and validate traditional imaging technologies. This is followed by a description of the use of HSI for biological analysis and medical diagnostics with emphasis on single-cell analysis using HSI.