Jing Zhang

Nature Communications, Published online: 04 September 2024; doi:10.1038/s41467-024-51125-y

Flow cytometry is often hindered by undesired fluctuations in fluorescence intensity. Here, the authors propose high-throughput fluorescence lifetime imaging flow cytometry, which enables imaging at a rate of over 10,000 cells per second and, therefore, enhances the capabilities of cellular analysis.

Nature Communications, Published online: 23 August 2024; doi:10.1038/s41467-024-51567-4

Microbot collectives can cooperate to accomplish complex tasks that are difficult for a single individual. Here, the authors report magnetic and light-driven ant microbot collectives that are capable of reconfiguring multiple assembled architectures.

Nature Electronics, Published online: 03 September 2024; doi:10.1038/s41928-024-01237-6

A wireless monitoring system that integrates an organic electrochemical transistor and a near-infrared inorganic micro-light-emitting diode on a thin parylene substrate can be used to monitor biomarkers such as glucose, lactate and pH.

Inspired by human skin, the innovative introduction of interlocked microridges can significantly improve the effective transmission of external stress from a sensitive layer to an interdigitated electrode, allowing bionic e-skin to exhibit an ultrahigh sensitivity (≈1502.5 kPa⁻¹) and a wide detection range (≈160 kPa). Moreover, such e-skin has the ability to detect a wide range of human vital signs and vibrations caused by sound wave.

Abstract

Electronic skin is increasingly receiving tremendous attention for its potential applications in medical rehabilitation and human-machine interaction. However, the trade-off between detection range and sensitivity of e-skin has not been well addressed, although various strategies have been proposed. Interlocked microridges between the epidermis and dermis can effectively transfer stress to mechanoreceptors, allowing human skin to exhibit excellent sensitivity even upon both subtle and large external stimuli. Herein, inspired by human skin, a novel bionic e-skin is developed in which interlocked microridges are introduced between the sensitive layer and interdigitated electrode. Thanks to the interlocked microridges, excellent compression capability and remarkable change of contact area between sensitive layer and interdigitated electrode can be achieved and the e-skin exhibits an ultrahigh sensitivity (≈1502.5 kPa⁻¹), excellent durability (10 000 cycles), a short response time (10 ms) as well as a wide detection range (≈160 kPa). Moreover, due to the effective transmission of external stress from a sensitive layer to an interdigitated electrode, such bionic e-skin has ability to detect a wide range of human vital signs and vibrations caused by sound waves. Such facile preparation of bionic interlocked microridges opens a new pathway to achieve high-performance e-skins and extend their application prospects in future wearable intelligent systems.

A supramolecular hydrogel containing light-responsive metal-coordination bonds can enable a spatiotemporal light-encoding strategy, creating frame and active regions in a single hydrogel without assembly. Consequently, the light-encoded hydrogels show biomimetic sequential and multistage shape-morphing behaviors beyond a single path. This light-encoding strategy will benefit the design of assembly-free hydrogel-based soft machines.

Abstract

Shape-morphing hydrogels can mimic the dynamism of living creatures and are popular for designing soft machines, such as actuators and robots. However, most existing shape-morphing hydrogels present a single morphing pathway between two shapes, sequential and multistage shape-morphing in real scenarios has rarely been captured. Although a strategy that assembles functional hydrogel components has been reported, it is likely to simultaneously increase the complexity and weaken the versatility of hydrogel machines. Here, a light-encoding strategy based on the dynamic coordination between the ferric iron and carboxyl group (Fe³⁺─COO⁻) to integrate the frame and actuating units into a single hydrogel without assembly is proposed. The spatiotemporal control of light irradiation is expected to make the light-encoding process sequential and reprogrammable. Results demonstrate that the light-encoded patterns determine the morphing route and further activate shape-morphing owing to swelling mismatch. The actuating units can be successively created by localized irradiation or elaborately turned by re-coordinating and light-encoding. This endows the encoded hydrogel with sequential and multistage shape-morphing behavior, similar to the living creatures. This strategy allows the design of assembly-free soft machines with sequential and multistage shape-morphing performance, which will benefit the design of more types of hydrogel machines.

The patterned biofilm consisting of live bacteria is achieved on chemically patterned quasi-liquid surface (QLS), with significant wetting and adhesion contrast for bacterial cells to aggregate at the sticky sacrifice regions. The patterned biofilm on QLS with optimized size and surface properties reduces the biofilm biomass and increases the antibiotic efficacy compared to dense biofilm.

Abstract

Bacterial cells within biofilms exhibit resistance to antibiotics, presenting persistent health risks. Current approaches to inhibit biofilm formation have limitations due to their poor biofilm morphological control. For instance, bactericidal surfaces suffer from the accumulation of dead cells that compromise their antibacterial efficacy, and existing antifouling surfaces fail to inhibit biofilm formation. In this work, exceptional biofilm suppression is achieved on quasi-liquid surfaces (QLS) with patterned surface chemistry where live bacterial cells are guided from slippery to sticky patterned destinations. These surfaces consist of 50 µm slippery and 10 µm sticky stripes. Live bacterial cells are directed to congregate on the sticky patterns, resulting in reduced biofilm biomass and surface coverage compared to uniform slippery surfaces. The patterned biofilm produces sparser extracellular matrix, thus reducing the barrier for antibiotic penetration and treatment. The innovative approach to direct cell migration on patterned QLS represents a promising strategy for inhibiting biofilm formation and combating biofilm-associated infections.

Nature Nanotechnology, Published online: 08 July 2024; doi:10.1038/s41565-024-01710-5

Room-temperature wafer-scale thermal evaporation of 20 different polycrystalline rare-earth-metal fluoride films for their use in 2D transistors is demonstrated.

Nature Nanotechnology, Published online: 01 July 2024; doi:10.1038/s41565-024-01676-4

Here the authors present a pH-sensitive DNA origami nanoswitch that hides ligands for death receptors and displays them as a cytotoxic hexagonal pattern in acidic tumour microenvironments. This reduces tumour growth in a murine model of breast cancer with minimal on-target, off-tumour toxicity.

Nature Communications, Published online: 02 September 2024; doi:10.1038/s41467-024-51949-8

Single cell analyses of non-human primates infected with one or two strains of Plasmodium vivax provide insights on the origin of polyclonality in patients and reveal an important population bottleneck occurring during pre-erythrocytic development.

Nature Communications, Published online: 31 August 2024; doi:10.1038/s41467-024-51891-9

Identifying rare cells is essential for advancing our understanding of complex biological systems and disease mechanisms. Here, authors propose scCAD, a method that combines cluster decomposition and anomaly detection to effectively identify rare cell types across diverse biological scenarios.

Nature Communications, Published online: 29 August 2024; doi:10.1038/s41467-024-51322-9

The controlled growth of large-area single-crystalline 2D semiconductors remains a significant challenge for their electronic applications. Here, the authors report a quasi-equilibrium growth method to synthesize inch-scale monolayer α-In2Se3 with high mobility and ferroelectric field-effect transistor performance.

Thin films of LiNbO₃ with high crystallinity and active telecom-band emissivity are fabricated without the need for excessively high-temperature anneals. This is achieved by performing Er ion implantation at moderately elevated temperatures, which are sufficient to dynamically annihilate the defects generated in collision cascades. These results represent an important step in building on-chip photonic quantum memory, essential for long-distance quantum communications.

Abstract

Lithium niobate (LiNbO₃) exhibits poor radiation resistance when conventionally implanted with Er at room temperature. To repair the structural disorder, high-temperature post-implantation anneals are typically required; however, such treatments can cause sample cracking and dopant redistribution, which are incompatible with device applications. The optimized approach is proposed by performing implants at elevated but acceptably low temperatures to in situ minimize the structural defects generated in the collision cascades, via so-called “dynamic defect annealing”. Thus, a gradual increase in Er optical activity is shown as a function of irradiation temperature in the range of 25–450 °C, in striking correlation with a decreasing trend for the residual disorder. The impact of moderate post-implantation anneals is also investigated by comparing the results of anneals of samples implanted at 25 °C and 450 °C. This comparison further confirms the higher optical activation of Er and lower residual structural disorder when the material is initially implanted at elevated temperatures. Based on these data, it is concluded that the use of dynamic defect annealing during the Er implantation of LiNbO₃ is a promising strategy for optimizing it as a quantum memory platform, resolving otherwise inevitable trade-offs.

Energy transfer from Eu²⁺ to Eu³⁺ is well known. This work demonstrates that the reverse energy transfer, from Eu³⁺ to Eu²⁺, is also possible. It occurs when the Eu²⁺ 4f⁶5d→4f⁷ emission lies in the near-infrared (NIR), such as in CaO:Eu²⁺,Eu³⁺. This shows that a full reduction of Eu³⁺ to Eu²⁺ is not required for the development of efficient NIR-emitting Eu-doped phosphors.

Abstract

While Eu²⁺ → Eu³⁺ energy transfer is well known, in this study the energy transfer from Eu³⁺ to Eu²⁺ is reported for the first time. The predominant condition for Eu³⁺ → Eu²⁺ energy transfer is a Eu²⁺ 4f⁵5d band at lower energy than the position of the Eu³⁺ 4f⁶[⁵D₀] level, which is fulfilled in Eu-doped CaO. X-ray powder diffraction, Eu Mössbauer spectroscopy and optical absorption measurements are employed to determine the Eu³⁺ and Eu²⁺ concentrations in the prepared CaO:1at.%Eu samples. Synthesis in an H₂/N₂ atmosphere and addition of graphite powder as a reducing agent to the starting mixture are found to result in respective Eu³⁺ and Eu²⁺ concentrations of 0.6–0.7% and 0.3–0.4%. For this sample, the Eu³⁺ → Eu²⁺ energy transfer efficiency is estimated to be high (> 90%). This is explained by the high oscillator strength of the 4f⁷ → 4f⁶5d excitation transition of the Eu²⁺ ion to which energy is transferred. As the Eu²⁺ 4f⁵5d band lies below the Eu³⁺ 4f⁶[⁵D₀] level, Eu³⁺ does not act as a killer center for the near-infrared (NIR) Eu²⁺ emission at about 720 nm. Therefore, a full reduction of Eu³⁺ is not required to attain a high quantum efficiency. Implications of the demonstrated Eu³⁺ → Eu²⁺ energy transfer for application of long wavelength Eu²⁺ phosphors are discussed.

The 980 nm pulsed laser can effectively restrain the self-heating, induce thermal-activated luminescence, result in the non-thermal coupling occupying state of ³P₀/³P₁, and yield a relative sensitivity (S _r) performance more than three times superior to that of down-shifting-based sensing. This provides a comprehensive analytical solution for achieving highly sensitive and stable temperature sensing based on energy transportation pathway manipulation.

Abstract

Despite the remarkable luminescent properties and temperature sensing capabilities of lanthanide materials, their photothermal effect in practical temperature measurement systems presents a major challenge to sensing reliability. Herein, taking Pr³⁺ as a typical exemplar, the influence of excitation wavelength and excitation approach on temperature sensing is systematically examined. The pulsed laser excitation method is identified as an efficient tactic to restrain the self-heating of luminescence materials. In accordance with this principle, it is discovered that diverse excitation wavelengths give rise to alterations in the internal energy transport channels and further impact the temperature sensing performance. The 980 nm pulsed laser can result in the non-thermal coupling occupying states of ³P₀/³P₁, which are recognized as thermal coupling energy levels in the conventional concept, and yield a relative sensitivity (S _r) performance more than three times superior to that of down-shifting-based sensing. The work provides a comprehensive analytical solution for achieving highly sensitive and stable temperature sensing based on excitation wavelength and working mode strategies.

Nature Communications, Published online: 28 August 2024; doi:10.1038/s41467-024-51576-3

Rare earth Nickelates, (RENiO3) host a bond disproportionation phase transition where oxygen 2p holes form at one of the Ni sites. This process results in a spin-disproportionation state where a singlet state is formed by the spin of the nickel and the spin of the oxygen hole at every other site. Here, Li et al find evidence of this spin-disproportionated state in a rareearth nickelate.

Nature, Published online: 28 August 2024; doi:10.1038/s41586-024-07871-6

A comprehensive cell atlas of the aged prefrontal cortex identifies two distinct cellular trajectories of ageing driven by specific glial and neuronal subpopulations, some of which are associated with clinicopathologic traits that define Alzheimer’s disease.

Bioinspired Sensors

In article number 2306079, Seungyong Han, Seung Hwan Ko, and co-workers introduce an overview of bioinspired materials employed in soft robotics, exploring their potential applications, challenges, and future research directions. Soft robotics, inspired by biological systems in nature, has achieved outstanding performance unattainable in unstructured environments. This approach will offer the opportunity to advance engineering systems as an innovative concept.

In this review, the recent advances of III–V semiconductor-based photodetectors are summarized from the aspects of synthetic approaches and detection applications. Their response to various electromagnetic wavelengths are comprehensively classified and compared. Based on the highlighted challenges and perspectives, this work can significantly enlighten the future development of III–V semiconductor-based photodetectors.

Abstract

The rapid advancement of main group III–V nanomaterials endows photodetectors (PDs) with enhanced performance. At present, various III–V nanomaterials are systematically investigated, whereof III–V semiconductors have attracted a successively increased attention that calls for a comprehensive summary which also can define the state-of-art for their further development. Herein, this work systematically introduces and discusses key aspects of the field. First, the advanced strategies for the preparation of III–V semiconductor materials and the device structures of the subsequent PDs based on these materials, pristine and doped, are addressed. The focus is then turned to their performance under the irradiation of various wavelengths, separately summarizing and comparing the photodetection properties under infrared, UV and visible light. Finally, challenges and future perspectives of III–V semiconductor-based PDs are highlighted. This review  enlightens the development of III–V semiconductor-based PDs, and their extended applications for optoelectronic devices in general.

Nature Communications, Published online: 26 August 2024; doi:10.1038/s41467-024-51574-5

Monitoring the biology of nucleoli remains challenging, particularly in the case of suspended cells and in high-throughput applications. Here, the authors report single-cell laser emitting cytometry, which can profile nucleoli in single cells and tissues in a label-free manner.

Blue-emitting 2D CsPbBr₃ nanoplatelets with varying Br/Pb ratios are synthesized using ZnBr₂, enhancing Br ion adsorption and passivating surface defects. This improved PLQY, extended lifetimes, and enhanced thermal, UV, and water stabilities. These NPLs show potential for quality lighting and display technologies, achieving a wide color gamut of 126.6% of NTSC and 94.5% of Rec. 2020 in prototype white LEDs.

Abstract

This study presents the Br-rich in situ synthesis of blue-emitting 2D CsPbBr₃ nanoplatelets (NPLs) with various Br/Pb ratios using ZnBr₂ as a Br precursor to enhance Br ion adsorption significantly. This leads to effective passivation of surface defects, particularly Pb−Br bonds, by increasing the positive charge density around Pb atoms, thus creating a stable bonding environment and reducing defect formation. Consequently, the photoluminescence quantum yield (PLQY) improves from 31.15% for a Br/Pb ratio of 2 to 87.2% for a ratio of 6. NPLs with a Br/Pb ratio of 6 also exhibit longer lifetimes (16.69 ns) and slower bleach recovery dynamics, indicating fewer non-radiative recombination pathways and effective exciton dynamics. Additionally, NPLs with the Br/Pb ratio of 6 demonstrated better thermal stability, with an activation energy of 124.3 meV, indicating stronger exciton binding. These NPLs also exhibited enhanced stability, with UV tolerance at 43.9% and water resistance at 23.8%, making them suitable for displays and lighting. Furthermore, Br-passivated CsPbBr₃ NPLs are used as blue emitters in prototype white LEDs, achieving a wide color gamut, 126.6% of the National Television Standards Committee and 94.5% of Rec. 2020, demonstrating their potential for high-quality lighting and advanced display technologies.

Nature Nanotechnology, Published online: 26 August 2024; doi:10.1038/s41565-024-01762-7

In situ evaporation of Eu and As onto InAs nanowires results in the mutual exchange of Eu from the shell with In from the core. This solid-state exchange reaction converts wurtzite InAs nanowires into Zintl Eu3In2As4.

Nature Communications, Published online: 23 August 2024; doi:10.1038/s41467-024-51567-4

Microbot collectives can cooperate to accomplish complex tasks that are difficult for a single individual. Here, the authors report magnetic and light-driven ant microbot collectives that are capable of reconfiguring multiple assembled architectures.

This work shows a study on 15 nm core@shell NaYF₄:Yb³⁺, Er³⁺@NaNdF₄:Yb³⁺ synthesized via an optimized thermal decomposition method. Due to excellent optical properties achieved under 808 nm excitation, e.g., effective emission, high relative sensitivity (1.44 %·K⁻¹), and resolution at a satisfactory level (0.63 K at 295 K), they are applied for bioimaging and temperature sensing inside aquatic invertebrate- D.magna.

Abstract

In biomedical and optical applications, multifunctional upconverting nanoparticles (UCNPs) play an essential role where non-invasive temperature sensing and imaging are necessary. UCNPs smaller than 20 nm, which can be excited under 808 nm wavelength, are particularly promising in this area and can be implemented in humans or other mammals. However, new versatile nanoprobes are still needed for biology, especially for challenging studies of small aquatic invertebrates. Such tools allow better monitoring and understanding of their physiology, biochemistry, and ecological responses, which is crucial due to the growing pollution of water reservoirs and climate change. Herein, multifunctional NaYF₄:Yb³⁺, Er³⁺@NaNdF₄:Yb³⁺ core@shell NPs (15 nm), forming stable aqueous colloids, exhibiting intense emissions under excitation in the first biological window (808 nm), and presenting high thermal sensitivity and resolution related to the thermally coupled energy levels of Er³⁺ ions, are designed and synthesized. Such properties of UCNPs are further utilized for optical imaging of aquatic invertebrates (Daphnia magna) and temperature detection inside their bodies under 808 nm excitation. This pioneering application of NaYF₄:Yb³⁺, Er³⁺@NaNdF₄:Yb³⁺ demonstrates the high potential of developed UCNPs for multifunctional applications, especially for bioimaging and temperature sensing within whole organisms.

Multidimensional Data Encoding

In article number 2402510, Jaume Ramon Otaegui, Jordi Hernando, Claudio Roscini, and co-workers obtain thermoresponsive multistate fluorescent emission from polymer films embedding core-shell microcapsules, loaded with a mixture of phase change materials (PCM) and a fluorescent dye. The combination of microcapsules containing different dyes and PCMs within the pixels allows for a straightforward construction of high security 3D information encryption and 4D data storage materials, whose state is controlled by suitable current application.

This Perspective discusses fundamental material limitations and device integration challenges that need to be addressed to bring metal halide perovskite thin-film devices from lasing under optical pumping to electrical pumping. These aspects include optical gain mechanisms, carrier recombination dynamics, electroluminescence efficiency roll-off, thermal runaway, and low-optical-loss layouts with compatible resonant cavity integration methods.

Abstract

Metal halide perovskite semiconductors hold a strong promise for enabling thin-film laser diodes. Perovskites distinguish themselves from other non-epitaxial media primarily through their ability to maintain performance at high current densities, which is a critical requirement for achieving injection lasing. Coming in a wide range of varieties, numerous perovskites delivered low-threshold optical amplified spontaneous emission and optically pumped lasing when combined with a suitable optical cavity. A progression toward electrically pumped lasing requires the development of efficient light-emitting structures with reduced optical losses and high radiative efficiency at lasing-level current densities. This involves a set of important trade-offs in terms of material choice, stack and waveguide design, as well as resonator integration. In this Perspective, the key milestones are highlighted that have been achieved in the study of passive optical waveguides and light-emitting diodes, and these learnings are translated toward more complex laser diode architectures. Finally, a novel resonator integration route is proposed that is capable of relaxing optical and electrical design constraints.

A naturally occurring fatty acid yields a set of adhesives with different properties

Samarium diiodide (SmI2) is a privileged, single-electron reductant deployed in diverse synthetic settings. However, generalizable methods for catalytic turnover remain elusive because of the well-known challenge associated with cleaving strong SmIII–O ...