Cell-selective fluorescent probes have emerged as essential tools for live-cell imaging, enabling the differentiation of specific cell types within complex biological systems. Unlike traditional antibody-based methods that target extracellular proteins, small-molecule probes can access intracellular environments and exploit diverse biochemical features for selective retention or activation. This perspective categorizes the mechanisms of cell selectivity into five principal strategies: Protein-oriented, carbohydrate-oriented, lipid-oriented, gating-oriented, and metabolism-oriented live-cell distinctions. Each class capitalizes on a unique cellular trait ranging from protein expression and membrane composition to transporter activity and metabolic enzyme presence. We discuss representative examples of each mechanism, outline a decision-tree workflow for elucidating a new probe's mode of action, and highlight how understanding these mechanisms is critical for both basic biological research and therapeutic probe design. Looking ahead, the development of such mechanism-informed cell-specific probes holds promise for advancing precision cell targeting in biomedical applications.
Fabricating macroscale smart actuators that can convert light energy into other forms of energy, especially mechanical and electrical energy, is of great significance. Herein, a simple and efficient 4D printed method for fabricating photomechanical actuators based on micro/nano-scale crystals is developed. The high versatility and generality of this method are successfully demonstrated using nine different types of photoresponsive crystalline actuators, including acylhydrazone-, anthracene-, olefin-, and azobenzene-based molecular crystals and covalent organic frameworks (COFs). The low-cost neutral silicone sealant elastomer is first chosen as the photomechanical 4D printing matrix. Notably, these actuators can be used to perform bionic motions (the first windmills spin using crystalline material, dragonflies fly, and sunflowers bloom) under the stimulation of visible light and can realize energy conversion from mechanical energy into electricity when coupled with a piezoelectric membrane. This work provides new insights into the design and manufacturing of smart photomechanical actuators and electricity generators and expands the application scope of COFs.
The electrochemical oxidation of biomass-derived platform molecule 5-hydroxymethylfurfural (HMF) represents a crucial pathway for green transformation into high-value chemicals, yet its reaction pathway selectivity, efficiency, and catalyst stability are strongly dependent on the electrolyte pH environment. Under alkaline conditions, high OH− concentration facilitates preferential aldehyde group oxidation and efficient deprotonation, enabling highly efficient synthesis of 2,5-furandicarboxylic acid, but simultaneously induces HMF self-degradation and complicates product separation. As pH decreases, the reaction mechanism shifts toward enhanced hydroxymethyl oxidation, leading to intermediate accumulation (such as 5-hydroxymethyl-2-furancarboxylic acid, 2,5-diformylfuran, and 5-formyl-2-furancarboxylic acid) with challenging selectivity control and significantly slowed reaction kinetics. This review comprehensively examines the systematic differences in HMF oxidation pathways and surface catalytic mechanisms across the full pH range from alkaline to acidic conditions. Addressing the distinct reaction characteristics and core challenges in alkaline, near-neutral, and acidic media, we systematically evaluate design strategies for high-efficiency electrocatalysts and explore reactor design aspects. Future research should focus on process integration (with tailored reactor design) for energy consumption reduction in alkaline systems, targeted synthesis of diverse oxidation products in near-neutral systems, and innovative catalyst development for acidic systems, thereby advancing the efficiency, selectivity, and practical application of HMF electrooxidation technologies across the entire pH spectrum through synergistic optimization of catalyst, reactor, and process.
The nonchemically amplified (nonCA) polymer resists, including ionic and non-ionic types, have achieved higher resolution and smaller line edge roughness (LER) than traditional chemically amplified ones. However, for polymer resists, chain entanglement is an inevitable limitation for the further reduction of LER. To overcome this problem, it is logical to apply the nonCA concept to molecule-based resists due to their advantages of monodispersity and small size. To date, only a few examples of ionic sulfonium salts-based nonCA molecular glass resists (nonCAMGRs) have been reported. They demonstrated high resolution and small LER well, but their electron beam sensitivity seemed less than ideal. To our knowledge, non-ionic sulfoxime oxime esters-based molecular resists were not reported yet, which leaves room for new round of more in-depth reserch on nonCAMGRs. Here, employing the excellent spirobixanthene backbone, we have first designed non-ionic sulfoxime oxime esters-based nonCAMGRs X4-NI-tf and X4-NI-tfb, for comparison, sulfonium salts-based nonCAMGRs X4-I-otfdm was designed. All exhibit favorable thermal properties (Td,5% > 200°C) and film-forming capabilities (RMSs <0.4 nm). Via EBL, X4-I-otfdm achieved higher resolution (16 nm, LER 1.4 nm) than X4-NI-tf and X4-NI-tfb (20 nm, LER1.6 nm). But contrast curve revealed that the sensitivity of X4-NI-tf and X4-NI-tfb (D100: 370 and 350 μC/cm2) was significantly higher than X4-I-otfdm (D100: 3300 μC/cm2), demonstrating that the sensitivity of sulfoxime oxime esters exceeds that of sulfonium salts and introduction of bromine can further enhance the sensitivity; based on above, X4-NI-tfb exhibited the lowest Z-factor and demonstrated the best overall performance. We believe that nonCAMGRs based on sulfoxime oxime esters represent a strong candidate for high-performance photoresists.
This study investigates the influence of hydrogen concentration at grain boundaries on the sensitivity of polycrystalline iron to hydrogen embrittlement using molecular dynamics simulations. These simulations reveal the diffusion behavior of hydrogen atoms at grain boundaries and their consequential impact on the hydrogen embrittlement sensitivity of iron alloys. The findings indicate that as the hydrogen concentration increases, both the yield strength and ultimate tensile strength of Fe-H alloys exhibit a declining trend. Moreover, the capture of hydrogen atoms at the grain boundaries significantly influences the fracture toughness of the material and promotes the formation and propagation of cracks. This study provides a novel theoretical basis for understanding and predicting the hydrogen embrittlement behavior of iron-based materials in hydrogen-rich environments, offering valuable insights for the design and development of Fe alloys with enhanced resistance to hydrogen embrittlement.
Control over charge transport in molecular–scale devices requires a deep understanding of how minute structural changes influence electronic properties. Here, we demonstrate dual transport regimes in tunnel junctions of n-alk-1-yne (CnA) molecules with gold electrodes driven by conformational bifurcation—the emergence of two nearly isoenergetic (planar and skewed) molecular conformers (dihedral angles α = 180° and α ≈ 65° at the alkyne terminus in the gas phase). Although the energy differences are small, these subtle conformational differences manifest as distinct transport behaviors, uncovered through unsupervised machine learning, which identified two junction groups: “short” and “long” chains, with distinct attenuation factors (βshort ≈ 1.0 vs. βlong ≈ 0.74) and contact conductances (Gc,short ≈ 200 μS vs. Gc,long ≈ 8 μS). This dramatic impact of the dihedral angle exceeds the impact of the inter-ring twist angle in biphenyl-based junctions and rivals changes induced by switching from gold to platinum electrodes or from monothiol to dithiol anchors in oligoacene and oligophenylene junctions. X-ray photoelectron spectroscopy (XPS) confirmed this bifurcation, linking the “short” and “long” groups to planar and skewed conformers, with dihedrals remarkably agreeing with the gas-phase values. This work establishes conformational bifurcation as a promising route for designing programmable nanotransport properties through anchor-group control.
While nuclear energy represents a low-carbon and high-efficiency energy source that plays a vital role in the global energy mix, the limitations of spent fuel reprocessing technology pose a major challenge to its sustainable development. The PUREX (plutonium uranium redox extraction) process is currently the dominant nuclear fuel reprocessing technology in the world. However, the key extractant in this process is tributyl phosphate (TBP), which degrades under intense radiation, high temperatures, and strong acidity. This leads to the production of dibutyl phosphate, monobutyl phosphate, and other degradation byproducts, which may reduce the extraction efficiency and trigger third-phase formation and equipment corrosion. This paper systematically reviews the degradation mechanisms of TBP and its diluents, the analytical technique suitable for characterizing degradation products, and the impact of degradation products on the post-treatment process. Additionally, optimization strategies employed for suppressing third-phase formation are discussed. This study offers a theoretical foundation and technical insights in optimizing the PUREX process and ensuring the safe operation of the post-treatment process.
Naphthalene, anthracene and pyridone endoperoxides are known to thermally release singlet oxygen. However, in the cycloreversion reaction, singlet oxygen is produced stoichiometrically; therefore, multiple singlet oxygen releasing modules are expected to be very useful in inducing apoptosis of cancer cells. Herein, we present a potential therapeutic agent presenting three-pyridone endoperoxide modules and a mitochondria targeting group. Compared to previously reported pyridone-based monofunctional endoperoxides, the triple endoperoxide is highly effective as evidenced by assays and fluorescence microscopy.
Lateral flow immunoassays (LFIAs) are low-cost, rapid, and easy to use for point-of-care testing (POCT), but the majority of the available LFIA tests are indicative, rather than quantitative, and their sensitivity in antigen tests are usually limited at the nanogram range, which is primarily due to the passive capillary fluidics through nitrocellulose membranes, often associated with non-specific bindings and high background noise. To overcome this challenge, we report a Beads-on-a-Tip design by replacing nitrocellulose membranes with a pipette tip loaded with magnetic beads. The beads are pre-conjugated with capture antibodies that support a typical sandwich immunoassay. This design enriches the low-abundant antigen proteins and allows an active washing process to significantly reduce non-specific bindings. To further improve the detection sensitivity, we employed upconversion nanoparticles (UCNPs) as luminescent reporters and SARS-CoV-2 spike (S) antigen as a model analyte to benchmark the performance of this design against our previously reported methods. We found that the key to enhance the immunocomplex formation and signal-to-noise ratio lay in optimizing incubation time and the UCNP-to-bead ratio. We therefore successfully demonstrated that the new method can achieve a very large dynamic range from 500 fg/mL to 10 μg/mL, across over 7 digits, and a limit of detection of 706 fg/mL, nearly another order of magnitude lower than the best reported LFIA using UCNPs in COVID-19 spike antigen detection. Our system offers a promising solution for ultra-sensitive and quantitative POCT diagnostics.
Color filters are essential components for optical modulation. However, conventional filters are restricted to operating exclusively in either reflective or transmissive mode. Furthermore, they suffer from limited UV and thermal stability, low color purity, and exhibit identical coloration on both surfaces. Herein, we propose a novel design strategy for trans-reflective color filters by integrating the absorptive properties of dye-doped polysulfone (PSU) with the diffractive capabilities of photonic crystals. This composite filter achieved broad-spectrum transmission with deep color outputs—yellow (0.410, 0.510), magenta (0.446, 0.231), and cyan (0.201, 0.425)—closely aligned with standard color space coordinates. By tuning the refractive index of CeO2@SiO2 nanoparticles to match dye-based PSU matrix, the transmittance of filters exceeded 70%. Moreover, dye-mediated absorption reduces the scattering light, thereby enhancing reflection color purity (full width at half maxima (FWHM) = 25 nm) and producing vibrant blue, green, and red hues. The incorporation of UV-absorbing CeO2@SiO2 nanoparticles effectively mitigated dye photodegradation, yielding exceptional UV stability (ΔT < 2% under prolonged UV exposure). The filters also exhibited outstanding thermal stability (ΔT < 1% after 30 min heat treatment at 230°C). This work establishes a robust materials design framework for multifunctional optical filters, advancing the development of high-fidelity dual-mode color systems for next-generation display technologies.
Cellulose, the dominant natural polymer on Earth, features a distinct molecular structure with extraordinary mechanical properties and tunable characteristics, making it attractive for gel systems. Although significant progress has been made, challenges remain in fully leveraging their functional potential and broadening practical applications. This review systematically examines the properties of cellulose and cellulose gels, exploring novel reinforcement strategies—across molecular, supramolecular network, and macroscale structure levels—to enhance mechanical, electrical, and thermal performance, while coordinating these properties for practical implementations. These advancements are exemplified in emerging fields such as flexible robotics, electronic skins, flexible energy storage devices, and human-machine interaction systems. This article thoroughly investigates the fundamental characteristics, multi-scale design approaches, performance enhancement mechanisms, and cutting-edge implementations of cellulose-based gels across diverse domains. It provides a comprehensive overview of these advanced materials and offers strategic insights and recommendations for future research and innovation.
In this review, the synthesis, functions, and applications of the polymers containing germanium and tin, which are heavy group 14 elements, in their polymer frameworks are summarized. Germanium and tin can form similar skeletal structures with their homologues carbon and silicon, whereas the polymers containing germanium and tin show unique properties derived from their large atomic radii and weak binding energies. For example, polygermane and polystannane exhibited light absorption in the UV–visible region and conductivity because of the σ-conjugation through the polymer main-chain constructed by σ-bonds between heavy elements. The σ-conjugation was affected by the conformational change of the polymer main-chain, and thermochromic properties can be induced. Furthermore, the weak bonds were able to be cleaved homolytically upon photoirradiation, and radicals were subsequently generated. By incorporating hypervalent heavy elements into the π-conjugated system, it was possible to modulate the electronic structures of the π-conjugated system through σ*–π* conjugation with highly coordinated elements. Finally, applications for organic solar cells, organic light-emitting materials, and chemical sensors have been achieved. Herein, representative synthetic methods and unique properties for creating smart materials with germanium and tin will be explained.