Tuning A-Site Cation Deficiency in Pr0.5La0.5BaCo2O5+ δ Perovskite to Realize Large-Scale Hydrogen Evolution at 2000 mA cm-2.

Industrial-level hydrogen production from the water electrolysis requires reducing the overpotential (η) as much as possible at high current density, which is closely related to intrinsic activity of the electrocatalysts. Herein, A-site cation deficiency engineering is proposed to screen high-performance catalysts, demonstrating effective Pr0.5- xLa0.5BaCo2O5+ δ (P0.5- xLBC) perovskites toward alkaline hydrogen evolution reaction (HER). Among all perovskite compositions, Pr0.4La0.5BaCo2O5+ δ (P0.4LBC) exhibits superior HER performance along with unique operating stability at large current densities (J = 500-2000 mA cm-2 geo). The overpotential of ≈636 mV is achieved in P0.4LBC at 2000 mA cm-2 geo, which outperforms commercial Pt/C benchmark (≈974 mV). Furthermore, the Tafel slope of P0.4LBC (34.1 mV dec-1) is close to that of Pt/C (35.6 mV dec-1), reflecting fast HER kinetics on the P0.4LBC catalyst. Combined with experimental and theoretical results, such catalytic activity may benefit from enhanced electrical conductivity, enlarged Co-O covalency, and decreased desorption energy of H* species. This results highlight effective A-site cation-deficient strategy for promoting electrochemical properties of perovskites, highlighting potential water electrolysis at ampere-level current density.

Programmed Targeting Pyruvate Metabolism Therapy Amplified Single-Atom Nanozyme-Activated Pyroptosis for Immunotherapy.

Increasing cellular immunogenicity and reshaping the immune tumor microenvironment (TME) are crucial for antitumor immunotherapy. Herein, this work develops a novel single-atom nanozyme pyroptosis initiator: UK5099 and pyruvate oxidase (POx)-co-loaded Cu-NS single-atom nanozyme (Cu-NS@UK@POx), that not only trigger pyroptosis through cascade biocatalysis to boost the immunogenicity of tumor cells, but also remodel the immunosuppressive TME by targeting pyruvate metabolism. By replacing N with weakly electronegative S, the original spatial symmetry of the Cu-N4 electron distribution is changed and the enzyme-catalyzed process is effectively regulated. Compared to spatially symmetric Cu-N4 single-atom nanozymes (Cu-N4 SA), the S-doped spatially asymmetric single-atom nanozymes (Cu-NS SA) exhibit stronger oxidase activities, including peroxidase (POD), nicotinamide adenine dinucleotide (NADH) oxidase (NOx), L-cysteine oxidase (LCO), and glutathione oxidase (GSHOx), which can cause enough reactive oxygen species (ROS) storms to trigger pyroptosis. Moreover, the synergistic effect of Cu-NS SA, UK5099, and POx can target pyruvate metabolism, which not only improves the immune TME but also increases the degree of pyroptosis. This study provides a two-pronged treatment strategy that can significantly activate antitumor immunotherapy effects via ROS storms, NADH/glutathione/L-cysteine consumption, pyruvate oxidation, and lactic acid (LA)/ATP depletion, triggering pyroptosis and regulating metabolism. This work provides a broad vision for expanding antitumor immunotherapy.

Engineering a hollow bowl-like porous carbon-confined Ru-MgO hetero-structured nanopair as a high-performance catalyst for ammonia borane hydrolysis.

Exploration of high-performance catalysts holds great importance for on-demand H2 production from ammonia borane (AB) hydrolysis. In this work, a hollow bowl-like porous carbon-anchored Ru-MgO hetero-structured nano-pair with high-intensity interfaces is made, using a tailored design approach. Consequently, the optimized catalyst shows AB hydrolysis activity with a turnover frequency value of 784 min-1 in aqueous media and 1971 min-1 in alkaline solvent. Robust durability is also achieved, with slight deactivation after a ten-cycle test. Combined experimental and theoretical calculations validate the positive function of the interface between Ru and MgO for facilitating H transfer and boosting water activation, thus leading to improved AB hydrolysis performance. This study could be valuable in guiding the upgradation of Ru catalytic systems, to advance their practical applications.

Multi-Enzyme Co-Expressed Nanomedicine for Anti-Metastasis Tumor Therapy by Up-Regulating Cellular Oxidative Stress and Depleting Cholesterol.

Tumor cells movement and migration are inseparable from the integrity of lipid rafts and the formation of lamellipodia, and lipid rafts are also a prerequisite for the formation of lamellipodia. Therefore, destroying the lipid rafts is an effective strategy to inhibit tumor metastasis. Herein, a multi-enzyme co-expressed nanomedicine: cholesterol oxidase (CHO) loaded Co─PN3 single-atom nanozyme (Co─PN3 SA/CHO) that can up-regulate cellular oxidative stress, disrupt the integrity of lipid rafts, and inhibit lamellipodia formation to induce anti-metastasis tumor therapy, is developed. In this process, Co─PN3 SA can catalyze oxygen (O2 ) and hydrogen peroxide (H2 O2 ) to generate reactive oxygen species (ROS) via oxidase-like and Fenton-like properties. The doping of P atoms optimizes the adsorption process of the intermediate at the active site and enhances the ROS generation properties of nanomedicine. Meantime, O2 produced by catalase-like catalysis can combine with excess cholesterol to generate more H2 O2 under CHO catalysis, achieving enhanced oxidative damage to tumor cells. Most importantly, cholesterol depletion in tumor cells also disrupts the integrity of lipid rafts and inhibits the formation of lamellipodia, greatly inhibiting the proliferation and metastasis of tumor cells. This strategy by up-regulating cellular oxidative stress and depleting cellular cholesterol constructs a new idea for anti-metastasis-oriented cancer therapy strategies.

Multi-enzyme Co-expressed Dual-Atom Nanozymes Induce Cascade Immunogenic Ferroptosis via Activating Interferon-γ and Targeting Arachidonic Acid Metabolism.

Immunotherapy is currently the most promising treatment strategy for long-term tumor regression. However, current cancer immunotherapy shows low response rates due to insufficient immunogenicity of tumor cells. Herein, we report a strategy to keep tumor cells highly immunogenic by triggering cascade immunogenic tumor ferroptosis. We developed a six-enzyme co-expressed nanoplatform: lipoxygenase (LOX) and phospholipase A2 (PLA2)-co-loaded FeCo/Fe-Co dual-metal atom nanozyme (FeCo/Fe-Co DAzyme/PL), which can not only induce initial immunogenic tumor ferroptosis through its own multi-enzyme mimetic activities but also up-regulate arachidonic acid (AA) expression to synergize with CD8+ T cell-derived IFN-γ to induce ACSL4-mediated immunogenic tumor ferroptosis. During this process, FeCo/Fe-Co DAzyme/PL can induce lipid peroxidation (LPO) by efficiently generating reactive oxygen species (ROS) and depleting GSH and GPX4 at tumor sites. Additionally, free AA released from PLA2 catalysis is converted into arachidonyl-CoA under the activation of ACSL4 stimulated by IFN-γ, which is further incorporated into phospholipids on membranes and peroxidized with the participation of LOX. Consequently, FeCo/Fe-Co DAzyme/PL can promote irreversible cascade immunogenic ferroptosis through multiple ROS storms, GSH/GPX4 depletion, LOX catalysis, and IFN-γ-mediated ACSL4 activation, constructing an effective pathway to overcome the drawbacks of current immunotherapy.

A Novel Near-Infrared Ytterbium Complex [Yb(DPPDA)2](DIPEA) with Φ = 0.46% and τobs = 105 µs.

The luminescent performances of near-infrared (NIR) lanthanide (Ln) complexes were restricted greatly by vibration quenching of X-H (X = C, N, O) oscillators, which are usually contained in ligands and solvents. Encapsulating Ln3+ into a cavity of coordination atoms is a feasible method of alleviating this quenching effect. In this work, a novel ytterbium complex [Yb(DPPDA)2](DIPEA) coordinated with 4,7-diphenyl-1,10-phenanthroline-2,9-dicarboxylic acid (DPPDA) was synthesized and characterized by FT-IR, ESI-MS and elemental analysis. Under the excitation of 335 nm light, [Yb(DPPDA)2](DIPEA) showed two emission peaks at 975 and 1011 nm, respectively, which were assigned to the characteristic 2F5/2 → 2F7/2 transition of Yb3+. Meanwhile, this ytterbium complex exhibited a plausible absolute quantum yield of 0.46% and a luminescent lifetime of 105 µs in CD3OD solution. In particular, its intrinsic quantum yield was calculated to be 12.5%, and this considerably high value was attributed to the near-zero solvent molecules bound to Yb3+ and the absence of X-H oscillators in the first coordination sphere. Based on experimental results, we further proposed that the sensitized luminescence of [Yb(DPPDA)2](DIPEA) occurred via an internal redox mechanism instead of an energy transfer process.

Defect-Rich Glassy IrTe2 with Dual Enzyme-Mimic Activities for Sono-Photosynergistic-Enhanced Oncotherapy.

The complexity, diversity, and heterogeneity of malignant tumors pose a formidable challenge for antitumor therapy. To achieve the goal of significantly enhancing the antitumor effect, nanomedicine-based synergistic therapy is one of the important strategies. Herein, we innovatively report a defect-rich glassy IrTe2 (G-IrTe2) with weak Ir-Te bond strength for synergistic sonodynamic therapy (SDT), chemodynamic therapy (CDT), and mild photothermal therapy (PTT). G-IrTe2 sonosensitizer under ultrasound (US) stimuli exhibits excellent reactive oxygen species (ROS) production performance. Besides, catalase (CAT)-like activity of G-IrTe2 can provide abundant oxygen to enhance the SDT effect. Then, the theoretical calculation verifies that US stimuli can easily make the irregular Ir-Te bond to be broken in amorphous IrTe2 and free electrons will be released to combine with the oxygen and further form singlet oxygen (1O2). Meanwhile, G-IrTe2 with peroxidase (POD)-like activity can also catalyze endogenous H2O2 to produce more ROS for chemodynamic therapy (CDT), which is conducive to better tumor ablation. Furthermore, the ROS produced by sono-/chemodynamic processes can cause mitochondrial dysfunction and further give rise to heat shock protein (HSP) downregulated expression, maximizing the efficiency of mild PTT. Therefore, such glassy IrTe2 with rich defect could be significantly involved in synergistic oncotherapy and then effectively achieve outstanding antitumor efficacy. This study provides a new research idea for expanding the application of inorganic glassy nanomaterials in promoting the therapeutic effect of tumors.

Hollow nanoparticles synthesized via Ostwald ripening and their upconversion luminescence-mediated Boltzmann thermometry over a wide temperature range.

Upconversion nanoparticles (UCNPs) with hollow structures exhibit many fascinating optical properties due to their special morphology. However, there are few reports on the exploration of hollow UCNPs and their optical applications, mainly because of the difficulty in constructing hollow structures by conventional methods. Here, we report a one-step template-free method to synthesize NaBiF4:Yb,Er (NBFYE) hollow UCNPs via Ostwald ripening under solvothermal conditions. Moreover, we also elucidate the possible formation mechanism of hollow nanoparticles (HNPs) by studying the growth process of nanoparticles in detail. By changing the contents of polyacrylic acid and H2O in the reaction system, the central cavity size of NBFYE nanoparticles can be adjusted. Benefiting from the structural characteristics of large internal surface area and high surface permeability, NBFYE HNPs exhibit excellent luminescence properties under 980 nm near-infrared irradiation. Importantly, NBFYE hollow UCNPs can act as self-referenced ratiometric luminescent thermometers under 980 nm laser irradiation, which are effective over a wide temperature range from 223 K to 548 K and have a maximum sensitivity value of 0.0065 K-1 at 514 K. Our work clearly demonstrates a novel method for synthesizing HNPs and develops their applications, which provides a new idea for constructing hollow structure UCNPs and will also encourage researchers to further explore the optical applications of hollow UCNPs.

Selenium Vacancy Engineering Using Bi2Se3 Nanodots for Boosting Highly Efficient Photonic Hyperthermia.

Despite bismuth-based energy conversion nanomaterials having attracted extensive attention for nanomedicine, the nanomaterials suffer from major shortcomings including low tumor accumulation, long internal retention time, and undesirable photothermal conversion efficiency (PCE). To combat these challenges, bovine serum albumin and folic acid co-modified Bi2Se3 nanomedicine with rich selenium vacancies (abbreviated as VSe-BS) was fabricated for the second near-infrared (NIR-II) light-triggered photonic hyperthermia. More importantly, selenium vacancies on the crystal planes (0 1 5) and (0 1 11) of VSe-BS with similar formation energies could be distinctively observed via aberration-corrected scanning transmission electron microscopy images. The defect engineering endows VSe-BS with enhanced conductivity, making VSe-BS possess outstanding PCE (54.1%) in the NIR-II biowindow and desirable photoacoustic imaging performance. Tumor ablation studies indicate that VSe-BS possesses satisfactory therapeutic outcomes triggered by NIR-II light. These findings give rise to inspiration for further broadening the biological applications of defect engineering bismuth-based nanomaterials.

Boosting Electrochemical Carbon Dioxide Reduction on Atomically Dispersed Nickel Catalyst.

Single-atom catalysts (SACs) with metal-nitrogen (M-N) sites are one of the most promising electrocatalysts for electrochemical carbon dioxide reduction (ECO2R). However, challenges in simultaneously enhancing the activity and selectivity greatly limit the efficiency of ECO2R due to the improper interaction of reactants/intermediates on these catalytic sites. Herein, we report a carbon-based nickel (Ni) cluster catalyst containing both single-atom and cluster sites (NiNx-T, T = 500-800) through a ligand-mediated method and realize a highly active and selective electrocatalytic CO2R process. The catalytic performance can be regulated by the dispersion of Ni-N species via controlling the pyrolysis condition. Benefitting from the synergistic effect of pyrrolic-nitrogen coordinated Ni single-atom and cluster sites, NiNx-600 exhibits a satisfying catalytic performance, including a high partial current density of 61.85 mA cm-2 and a high turnover frequency (TOF) of 7,291 h-1 at -1.2 V vs. RHE, and almost 100% selectivity toward carbon monoxide (CO) production, as well as good stability under 10 h of continuous electrolysis. This work discloses the significant role of regulating the coordination environment of the transition metal sites and the synergistic effect between the isolated single-site and cluster site in enhancing the ECO2R performance.

Author Correction: Bismuthene for highly efficient carbon dioxide electroreduction reaction.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Bismuthene for highly efficient carbon dioxide electroreduction reaction.

Bismuth (Bi) has been known as a highly efficient electrocatalyst for CO2 reduction reaction. Stable free-standing two-dimensional Bi monolayer (Bismuthene) structures have been predicted theoretically, but never realized experimentally. Here, we show the first simple large-scale synthesis of free-standing Bismuthene, to our knowledge, and demonstrate its high electrocatalytic efficiency for formate (HCOO-) formation from CO2 reduction reaction. The catalytic performance is evident by the high Faradaic efficiency (99% at -580 mV vs. Reversible Hydrogen Electrode (RHE)), small onset overpotential (<90 mV) and high durability (no performance decay after 75 h and annealing at 400 °C). Density functional theory calculations show the structure-sensitivity of the CO2 reduction reaction over Bismuthene and thicker nanosheets, suggesting that selective formation of HCOO- indeed can proceed easily on Bismuthene (111) facet due to the unique compressive strain. This work paves the way for the extensive experimental investigation of Bismuthene in many different fields.

Constructing an ultra-adsorbent based on the porous organic molecules of noria for the highly efficient adsorption of cationic dyes.

A novel Noria-POP-1 material has been successfully synthesized by the simple polymerization of the porous organic molecules of noria and aryl diamines. Noria-POP-1 displayed excellent adsorption capacity for cationic dyes from water with selective removal ability. The adsorption experiments show that Noria-POP-1 displays a remarkable capability to selectively adsorb and separate methylene blue with an adsorption capacity of 2434 mg g-1, which is the highest value obtained so far for porous organic polymers.

Synthesis and Near Infrared Luminescence Properties of a Series of Lanthanide Complexes with POSS Modified Ligands.

A polyhedral oligomeric silsesquioxanes (POSS) modified 8-hydroxyquinoline derivative (denoted as Q-POSS) was synthesized and used as a ligand to coordinate with lanthanide ions to obtain a series of lanthanide complexes Ln(Q-POSS)3 (Ln = Er3+, Yb3+, Nd3+). The as-prepared lanthanide complexes have been characterized by FT-IR, UV⁻Vis, and elemental analysis. All these complexes showed the characteristic near-infrared (NIR) luminescence originated from the corresponding lanthanide ions under excitation. Compared with the unmodified counterparts LnQ3 (HQ = 8-hydroxyquinoline), the Ln(Q-POSS)3 complexes showed obviously increased emission intensity, which was ascribed mainly to the steric-hindrance effects of the POSS moiety in the ligands. It is believed that the POSS group could suppress undesired excimer formation and intermolecular aggregation, thus decreasing the concentration quenching effect of the corresponding lanthanide complexes.

Renal Clearable Bi-Bi2S3 Heterostructure Nanoparticles for Targeting Cancer Theranostics.

Recent development of precise nanomedicine has aroused an overwhelming interest in integration of diagnosis and treatment for cancers. Designing renal-clearable and targeting nanoparticles (NPs) has specific cancer theranostic implications and remains a challenging task. In this work, the ultrasmall folic acid (FA) and bovine serum albumin-modified Bi-Bi2S3 heterostructure nanoparticles NPs (Bi-Bi2S3/BSA&FA NPs) with excellent computed tomography (CT) and photoacoustic imaging abilities and outstanding photothermal performances were synthesized in an aqueous phase route via a simple method. Bi-Bi2S3/BSA&FA NPs have the following criteria: (i) Bi-Bi2S3/BSA&FA NPs with heterostructure possess better stability than Bi NPs and higher Bi content than Bi2S3 NPs, which are conducive to the enhancement of CT imaging effect; (ii) Bi-Bi2S3/BSA&FA NPs with FA molecules on the surface could target the tumor site effectively; (iii) Bi-Bi2S3/BSA&FA NPs could inhibit tumor growth effectively under 808 nm laser irradiation; (iv) ultrasmall Bi-Bi2S3/BSA&FA NPs could be cleared through kidney and liver within a reasonable time, avoiding a long-term retention/toxicity. Therefore, the renal clearable Bi-Bi2S3/BSA&FA NPs are a promising agent for targeting cancer theranostics.

The mixed-ligand strategy to assemble a microporous anionic metal-organic framework: Ln3+ post-functionalization, sensors and selective adsorption of dyes.

A unique microporous anionic metal-organic framework, namely [Zn2(btb)2(bbis)](Me2NH2)2·6DMF (1), has been synthesized and structurally characterized [bbis = bis(4-benzylimidazol-ylphenyl)sulfone and H3btb = 4,4',4''-benzene-1,3,5-triyltribenzoic acid]. This compound exhibits a 4-fold interpenetrated anionic framework with ins topology. The post-synthetic cation exchange of 1 with Eu3+, Tb3+, Dy3+ and Sm3+ afforded lanthanide(iii)-loaded materials. Eu3+@1 and Tb3+@1 can be used as the potential luminescent probes in nitrobenzene. The adsorption behavior of 1 towards organic dyes was investigated, revealing rapid and selective separation of methylene blue.

Highly fluorescent nitrogen-doped carbon dots with excellent thermal and photo stability applied as invisible ink for loading important information and anti-counterfeiting.

High quantum yields (QY) and stable performances are prerequisites for implementing carbon dots in practical applications. In this study, we demonstrate that nitrogen-doped carbon dots (N-CDs), which were prepared via the hydrothermal treatment of citric acid (CA) and tris(hydroxymethyl)methyl aminomethane (Tris), have a high QY of 75%, together with excellent thermal and photo stability. These N-CDs deliver an excellent thermal stability performance over the temperature range of 25 °C to 95 °C, and even at a heating temperature of 90 °C for 360 min. Upon exposure to UV illumination with a radiant intensity of 20 mW cm-2, 96% fluorescence intensity is retained. This florescence stability performance is probably due to the chemical composition and steric effect of the nitrogen-doping agent. Furthermore, the remarkable optical properties of these N-CDs allow them to be used as invisible ink for loading important information and advanced anti-counterfeiting.

Mycobacterium tuberculosis proteome microarray for global studies of protein function and immunogenicity.

Poor understanding of the basic biology of Mycobacterium tuberculosis (MTB), the etiological agent of tuberculosis, hampers development of much-needed drugs, vaccines, and diagnostic tests. Better experimental tools are needed to expedite investigations of this pathogen at the systems level. Here, we present a functional MTB proteome microarray covering most of the proteome and an ORFome library. We demonstrate the broad applicability of the microarray by investigating global protein-protein interactions, small-molecule-protein binding, and serum biomarker discovery, identifying 59 PknG-interacting proteins, 30 bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) binding proteins, and 14 MTB proteins that together differentiate between tuberculosis (TB) patients with active disease and recovered individuals. Results suggest that the MTB rhamnose pathway is likely regulated by both the serine/threonine kinase PknG and c-di-GMP. This resource has the potential to generate a greater understanding of key biological processes in the pathogenesis of tuberculosis, possibly leading to more effective therapies for the treatment of this ancient disease.

One-step synthesis of water-soluble hexagonal NaScF4:Yb/Er nanocrystals with intense red emission.

Water-soluble hexagonal NaScF4:Yb/Er nanocrystals have been directly synthesized via a facile one-step hydrothermal route. The as-prepared nanocrystals were monodisperse and could form stable colloidal solutions in polar solvents, such as water and ethanol. The novel NaScF4:Yb/Er nanocrystals exhibited intrinsic intense red upconversion emission, in contrast to other lanthanide-doped fluoride nanocrystals. Remarkably, the upconversion emission intensity was enhanced ∼6.8 times through the coating of an active-shell (containing Yb(3+)) surrounding the NaScF4:Yb/Er core nanocrystals, owing to surface passivation effect and efficient energy transfer from Yb(3+) ions in both the core and the shell to Er(3+) ions. These water-soluble hexagonal NaScF4:Yb/Er nanocrystals with intense red emission are ideal for a variety of in vitro and in vivo biological imaging applications.