Chloramphenicol (CAP) residues in milk pose severe health risks, yet current detection methods (e.g., chromatography-mass spectrometry) suffer from complexity and high costs. In this work, we address this gap by developing an ultrasensitive aptamer-gated graphene Field-effect biosensor. A self-assembled Aptamer-functionalized solution-gated graphene transistor (Apt-SGGT) was engineered via systematic optimization of aptamer surface density to overcome spatial-confinement limitations and enhance conformational switching efficiency. We applied the Apt-SGGT biosensor to the analytical determination of CAP in actual skim milk samples, achieving a detection limit as low as 21.5 pM with a spiked recovery rate of 97.65 % +/- 5.72 %. This study not only presents a promising platform for the rapid, on-site detection of antibiotic residues in complex food matrices but also provides a generalizable interfacial engineering strategy to enhance the performance of aptamer-based field-effect biosensors.

The development of hydrogel dressings that exhibit excellent moisturizing, antibacterial, and pro-healing properties is an urgent need in the field of wound healing. This study designs a multifunctional hydrogel dressing (QCPVA-ZnO) to address this challenge by incorporating a quaternized nanocellulose‑zinc oxide hybrid (QCNC-ZnO) into a polyvinyl alcohol/chitosan matrix. QCPVA-ZnO exhibited excellent moisture retention and breathability, with a water vapor transmission rate of 2440 g·m-2·day-1 and an oxygen permeability rate of 111 g·mm/m2·day·kPa, which could be attributed to the synergistic effect of its porous structure and hydrophilic cross-linked network. The experiment of the full-thickness skin defect model in mice showed that QCPVA-ZnO had significant healing promoting ability, with a wound healing rate of 97.6% by day 11. This can be attributed to QCNC-ZnO endowing QCPVA-ZnO with a good bactericidal rate of 99%, which thereby enabled the latter to effectively control infections, reduce inflammatory reactions, and further promote angiogenesis and epidermal regeneration. In addition, biosafety evaluations indicated that QCPVA-ZnO had a cell survival rate of over 90% and hemolysis of less than 2%, demonstrating good biocompatibility. This study improves the moisturizing, air permeability, antibacterial and healing promoting functions of the hydrogel, providing a new idea for the development of multi-functional wound dressings.

Seeking a more efficient way to deal with the treatment of complex wounds has always been an urgent need. Zinc-doped carbon dots (Zn-CDs) are proposed to prepare hydrogel based on carboxymethyl chitosan. The results showed that Zn-CDs with excellent antibacterial property were formed by the coordination bond between CDs and zinc ions, molecular network structure obtained by hydrogen bond between carboxymethyl chitosan and Zn-CDs was cross-linked to form Zn-CDs based hydrogel (ZCBCH). ZCBCH exhibited excellent adhesion with the shear strength of 2.39 kPa, water vapor permeability with moisture vapor transmission rate of 26.3 g·m-2·day-1, antibacterial activity to Staphylococcus aureus and Escherichia coli, absorption capacity in deionized water, PBS, and 1 M NaCl solution, and blood compatibility with no hemolysis. More importantly, promoting wound healing and skin tissue regeneration is achieved by augmenting collagen encapsulation in ZCBCH with a recovery rate of 95.79%, a cell viability of 109.90%, in vitro hemolysis of 2.75%, and no toxicity to organs. The hydrogel with excellent properties prepared in this study is expected to achieve practical applications in the medical field.

Increasing miniaturization and integration of modern electronic devices has created an urgent need to develop effective strategies for achieving lightweight and flexible materials with integrated electromagnetic interference (EMI) shielding and thermal management properties. Herein, molybdenum carbide (MoC) with high electrical conductivity and magnetic iron sulfide (Fe7Ss) with strong magnetic responsiveness were introduced into an aramid nanofiber (ANF) framework via vacuum-assisted self-assembly to fabricate multifunctional MoC@Fe7Ss/ ANF composite films. The synergistic coupling of MoC and Fe7Ss forms continuous conductive and polarization networks, while the ANF matrix provides structural integrity and flexibility. As a result, the MoC@Fe7Ss/ANF-4 composite film exhibited a high tensile strength of 199.2 MPa and remarkable toughness of 9.0 MJ m- 3. Meanwhile, the composite films achieved an excellent in-plane thermal conductivity of 13.61 W m- 1 K-1 and rapidly heated to 179 degrees C under a low voltage of 4 V demonstrating outstanding electrothermal performance. Moreover, a high electrical conductivity of 1873.5 S m- 1 and an EMI shielding effectiveness of 57.08 dB were achieved. This work provides new insights into the design of multifunctional flexible ANF-based composite films with integrated mechanical properties, thermal management, electrothermal performance, and EMI shielding properties.

Acetamiprid (ACE) can accumulate in the environment through the food chain, potentially endanger human health. In this experiment, zinc-cobalt bimetallic metal organic framework (Zn/Co MOF) was synthesized and used to activate peroxymonosulfate (PMS) for the removal of ACE from water. The degradation efficiency of ACE could achieve approximately 96.93% after 90 min. Through the synergistic effect of Zn and Co bimetallic sites, ACE was degraded via a Fenton-like reaction, while reactive oxygen species (SO4 & sdot;-, & sdot;OH, O2 & sdot;-, and 1O2) participated in the process. The high catalytic activity of Zn/Co MOF led to the degradation of ACE through the formation of a series of low-toxicity intermediates, and partial mineralization to CO2 and H2O. In addition, Zn/Co MOF remained effective under broad pH conditions (pH 5-11) and temperatures (5-45 degrees C). This system had excellent degradation effects in actual water, with degradation rates of 95.42% and 95.18% after 90 min in the Pai River and Liren Lake, respectively. With its high catalytic performance, the Zn/Co MOF is expected to become an ideal catalyst that could be used to remove pesticide residues in water.

The selective transformation of lignin into valuable products remains challenging due to its structural heterogeneity and tendency to undergo recondensation. Here we report a spatially engineered bifunctional core-shell catalyst, Ni@H-beta, featuring nanodispersed Ni species on the external shell of a zeolite containing Brønsted acid sites within the core. This architecture enables a relay catalytic process involving hydrogenation on the Ni-rich surface followed by acid-catalyzed deoxygenation within the microporous framework. Under optimized conditions, Ni@H-beta achieves complete liquefaction of enzymatic hydrolysis lignin without char formation, yielding 50.1 wt% monomers predominantly composed of jet-fuel-range cycloalkanes. Operando NMR spectroscopy combined with density functional theory reveals a hydrogenation-first pathway that reduces deoxygenation barriers and enhances selectivity. Integrated process simulation, techno-economic analysis and life-cycle assessment further indicate that the EHL-to-jet-fuel process is economically competitive and environmentally advantageous compared with conventional petroleum-derived jet fuel.

Poly(lactic acid) (PLA), a biodegradable polyester derived from renewable feedstocks, exhibits inherent brittleness, limited thermal stability, and uncontrolled degradability, which restricts its broader application as a sustainable biomaterial. Constructing robust and well-organized interfacial architectures offers an effective strategy to overcome these challenges. In this study, a rationally designed carbon quantum dots (CQDs)@titanium dioxide (TiO2) nanonetwork was employed to reinforce PLA composites and elucidate how CQDs@TiO2 modulates their structural features, interfacial characteristics, and overall properties. It was demonstrated that embedding CQDs@TiO2 into PLA accelerated its degradation behavior in hydrolysis, phosphate-buffered saline (PBS) immersion, and soil burial tests. Meanwhile, the thermal resistance, overall thermal stability, and crystallization behavior of PLA were substantially enhanced due to the nucleation and thermal barrier effects of the CQDs@TiO2 nanonetwork. Moreover, the uniform morphology and compatibility of CQDs@TiO2 enabled homogeneous dispersion and effective stress transfer in PLA, leading to simultaneous enhancements in tensile modulus, strength, elongation, and toughness. Specifically, the tensile modulus, tensile strength, and elongation at break of PLA/CQDs@TiO2 composites increased by 11%, 44%, and 107%, respectively, compared to pure PLA. This study provides an efficient and sustainable strategy for tailoring the mechanical, degradability, and thermal properties of PLA composites.

Developing bio-based food packaging films with excellent mechanical, preservation, and degradation properties is an urgent need in the field of food packaging. This study proposed to prepare a multifunctional food packaging film by incorporating zinc-doped carbon dots (Zn-CDs), quaternized chitosan (QCS), and tannic acid (TA) into konjac glucomannan (KGM) to address the mentioned challenge. KGM-QCS-TA-ZnCDs film (KQTZF) presented excellent mechanical properties with the tensile strength of 69.73 MPa, elongation at break of 15.88%, and tensile modulus of 19.79 GPa, which can be achieved through better interfacial bonding caused by hydrogen bonding and coordination bonding. The preservation experiment of plums showed a freshness preservation period of 9 days indicating excellent preservation performance, which can be attributed to the fact that good sterilization property bactericidal rate of 99%, water barrier property of 37 g center dot m/(m2 center dot h center dot Pa), oxygen molecule permeability of 12.29 g center dot m/(m2 center dot h center dot Pa), and free radical scavenging rate of 90% were endowed to KQTZF by the synergistic effect of Zn-CDs, QCS, and TA. Furthermore, the synergistic effect of Zn-CDs, QCS, and TA also accelerated the degradation rate of KQTZF in water, PBS, and soil, demonstrating good environmental friendliness and sustainability. The simultaneous improvement of mechanical properties, biodegradability, and preservation performance of food packaging films in this study provides new ideas for the development of multifunctional fruit preservation packaging materials.

The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system has become a powerful genome-editing tool that uses RNA-DNA pairing to cleave target DNA with protospacer adjacent motif (PAM) sequences. While its primary function is well-studied, secondary activities remain poorly understood, causing unintended off-target effects. This study reports for the first time that Cas9 specifically cleaves the 5' overhang of the non-target strand (NTS) in target double-stranded DNA. This specific cleavage requires an additional PAM element at the NTS 5' region, is mediated by Cas9's RuvC domain, and is regulated by the HNH domain. It depends on the exact positioning of the NTS 5' end, but not on the overhang homopolymer sequence or overhang length. Adequate single-guide RNA-DNA complementarity is also essential. This discovery potentially advances our understanding of Cas9's enzymatic versatility to enhance genome-editing precision and efficacy and offers new nucleic acid detection strategies. Based on this cleavage, we developed a sensitive assay for Severe Acute Respiratory Syndrome Coronavirus 2 pseudovirus down to 2.4 copies μL-1, demonstrated extremely high sensitivity in diagnostic applications.

Bisphenol A (BPA), as a synthetic organic pollutant, threatened the human body through food packaging, drinking water, and even skin contact. It could accumulate in the body and cause toxicological damage. Therefore, it was important to develop efficient and accurate BPA detection sensors. This study prepared cerium-doped ZIF-8 carbon materials (Ce@ZIF8/C) through doping bimetals on carbon-based metal-organic framework (MOF). The carbon material exhibited more mesopores and defect structures, and Ce effectively improved its electrochemical catalytic performance. The detection concentration range of the Ce@ZIF8/C-modified solution-gated graphene transistors was 30 nM to 1 μM, with a limit of detection (LOD) of 10 nM. The Ce@ZIF8/C-modified solution-gated graphene transistors could perform real-time detection of BPA in drinking water and milk samples, with detection accuracies of 114.59 ± 5.96% and 107.45 ± 3.75%, respectively. This indicated its potential for detecting BPA in drinking water and milk.

The development of multifunctional composite films integrating robust mechanical strength, potent antibacterial activity, and efficient electromagnetic interference (EMI) shielding is critical for advancing next-generation smart materials. Herein, the rational engineering of CEL@ZnO/MXene composite films was achieved by the in-situ growth of ZnO nanoparticles on cellulose substrates and by synergistically harnessing the unique physicochemical attributes of ZnO and two-dimensional MXene nanosheets. This interfacially engineered and network-reinforced structure endowed the CEL@ZnO/MXene 5:5 composite film with superior mechanical properties, including a tensile strength of 32.5 MPa, a Young's modulus of 2.35 GPa, and an elongation at break of 1.87% achieving a balanced integration of strength, stiffness, and flexibility. In addition, the CEL@ZnO/ MXene 5:5 composite film exhibited potent bioactive functionality by achieving antibacterial efficiencies of 86.2% against Escherichia coli, 89.4% against Staphylococcus aureus, and antioxidant activity exceeding 80%, which in turn mitigates bacterial proliferation and oxidative stress. Furthermore, the obtained CEL@ZnO/MXene 5:5 composite film exhibits an EMI shielding property of 38.67 dB across the X-band (8.2-12.4 GHz) with reflection coefficients consistently above 0.8, indicating stable properties dominated by surface reflection complemented by controlled absorption. This study highlights the extensive application potential of the composite films in antibacterial protection, environmental safety, and electronic equipment shielding due to combined advantages in mechanical robustness, effective antibacterial activity, and electromagnetic interference shielding.

There is considerable interest in the ability to modulate biological processes with magnetic fields. Here we demonstrate a strategy for selecting aptamers that exhibit enhanced binding to paramagnetic metal ions under a strong magnetic field. Using a high-magnetic-field (HM)-SELEX method targeting Co2+, we identified two classes of aptamers with magnetically-modulated binding behavior. One displayed a gradual 2-3-fold increase in affinity as magnetic field strength increased, while the other went from minimal target binding at ambient field strength to an affinity of ~200 μM at ≥ 6 T. Molecular simulations revealed that the magnetic field induces a global conformational rearrangement by enhancing aptamer-metal electrostatic interactions, optimizing the coordination geometry of the nucleotides. Chemical footprinting and mutational analysis confirmed the role of certain conformational changes in magnetically-induced ion binding. These results suggest opportunities to generate aptamer switches that can be used to manipulate biorecognition processes via an externally applied magnetic field in diverse applications.

Background G-quadruplex (G4) DNAzyme is an artificial peroxidase mimic formed by the interaction of G4 and hemin. Due to the advantages such as lower cost, easier synthesis, and excellent biocompatibility, G4/Hemin DNAzyme holds significant potential for applications in biosensing, catalysis, and nanotechnology. However, the practical application of G4/Hemin DNAzyme in efficient catalytic reactions is limited by inherent drawbacks, particularly its relatively low catalytic activity, while the dynamic regulation of its activity also remains a challenge. Results In this work, we introduce a straightforward mechanochemical strategy to enhance and modulate the G4/Hemin activity by employing dsDNA as molecular clamps. The observed activity enhancement was not due to increased G4/Hemin affinity, but may probably attributed to perturbation of G4 conformation through mechanical stretching of the molecular clamps, leading to an increase in the maximum reaction velocity (Vmax) or turnover number (Kcat). It is also demonstrated that molecular clamp modulation can enhance the resistance of G4/Hemin to Pb2+ interference, maintaining high enzymatic activity even at Pb2+ concentrations up to 10 μM, also presenting a critical advancement for applications in complex environments. Significance and novelty This work addresses critical limitations of G4/Hemin DNAzymes such as low activity and poor environmental robustness, offering a transformative tool for biosensing and catalytic applications.

BACKGROUND:Copper is a vital trace element that plays a crucial role in various physiological processes due to its ability to exist in multiple oxidation states. Inspired by natural enzymes, researchers have developed copper-based nanozymes that mimic enzyme functions, offering cost-effective and stable alternatives to traditional enzymes. Despite their promising properties, the design and synthesis of these nanozymes can be complex and challenging. To address this issue, this work explores an intuitive approach to construct "soft" nanozymes simply by binding Cu2+ with its aptamers to form Cu(II)-aptamer complexes. RESULTS:Using a screening strategy, we identified a specific aptamer against Cu2+, designated P8, that significantly enhanced peroxidase-like activity when complexed with Cu2+, demonstrated by a notably smaller Km value. Furthermore, we investigated the effects of various lengths of a "molecular clamp" on the conformational dynamics of the P8 aptamer, which perturbs the encapsulation of Cu2+ and modulated its peroxidase activity. Our findings indicate that optimizing the molecular clamp to a moderate length (Nd = 20) can further enhance the peroxidase activity of the Cu2+-P8 complex. The peroxidase-like soft nanozymes based on copper(II)-aptamer complexes were finally utilized for label-free detection of EDTA. The developed colorimetric sensing method exhibits outstanding detection capabilities for EDTA in Sprite and mineral water samples, achieving an extended dynamic range that accommodates higher concentrations through the incorporation of molecular clamps. SIGNIFICANCE AND NOVELTY:This work highlights a novel and straightforward approach to generate and improve the enzymatic properties of copper-based nanozymes. The strategy to regulate the enzymatic activity effectively addresses the limitations of narrow detection ranges commonly observed in traditional methods.

Achieving simultaneous sustainability and property is a great challenge for current thermally managed composite films. The study proposes to prepare all-biomass derived nanocomposite films with excellent mechanical, thermal, and degradation properties by self-assembling carbon quantum dots (CQDs) and carbon nanosheets (CNSs) from cellulose nanofibers (CNFs). The results showed that the nanocomposite film with CQDs1@CNSs1/CF exhibited the best comprehensive properties with thermal conductivity of 0.817 W m-1 K-1, tensile strength of 39.60 MPa, elongation at break of 6.26%, tensile modulus of 5.34 GPa, degradation residual rate in water of 86.02%, degradation residual rate in PBS of 66.67%, and degradation residual rate in buried of 52%. The all-biomass derived nanocomposite films regarding the excellent thermal conductivity, biodegradability, and mechanical properties can be available with thermal management and excellent sustainability.

INTRODUCTION:Angelica sinensis is one of the most popular traditional Chinese medicines (TCM) and has been extensively used to treat various diseases. Hundreds of endogenous ingredients have been isolated and identified from this herb, but their spatial distribution within the plant root is largely unknown. OBJECTIVES:In this study, we tried to investigate and map within-tissue spatial distribution of metabolites in Angelica sinensis roots. MATERIAL AND METHODS:After optimization of experiment conditions, the 1,5-diaminonaphthalene (1,5-DAN) was chosen as the matrix and was sprayed on the surface of root sections. Then matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) was employed to perform in situ detection and obtain detail spatial distribution information of metabolites in Angelica sinensis roots. RESULTS:The spatial distributions of a wide range of metabolites including organic acids, amino acids, oligosaccharides, and phospholipids were characterized and visualized in Angelica sinensis roots. Majority of these metabolites were located in the phloem and xylem, while ferulic acid was mainly present in the cork layer. The results revealed a dramatic metabolic heterogeneity among different regions of the roots and distinct spatial distribution patterns of different metabolites. Additionally, the metabolic pathways involved in the biosynthesis of choline were also successfully localized and visualized. CONCLUSION:This study comprehensively characterized the spatial distribution of metabolites in Angelica sinensis roots, which would prompt the understanding of its chemical separation, biosynthesis, and pharmacological activities.

Achieving the simultaneous improvement of mechanical, degradation, and preservation properties is being a great challenge of current preservation films. Carbon quantum dots (CQDs) are proposed to prepare composite films with excellent mechanical, degradation, and preservation properties based on zein and chitosan. The result showed that the addition of CQDs improved the strength, stiffness, and toughness of zein composite films attributing to the stable and compact network structure formed by electrostatic interaction and hydrogen bonding. Also, adding CQDs promotes the degradation of zein composite films in the water and phosphate-buffered saline (PBS) environment while they alleviated the degradation in the soil environment demonstrating the stability in the soil. Among all the film samples, the composite films formed by zein, chitosan, Polyethylene glycol, and CQDs exhibited the best comprehensive properties with the tensile strength of 24.42 MPa, tensile modulus of 0.93 GPa, elongation at break of 8.39%, hydrolysis rate of 68.37%, PBS degradation rate of 27.48%, buried degradation rate of 71.71%, and preservation life to cherry tomatoes of more than 37 days. The composite films in this study are expected to play a significant role in the field of food preservation films in view of achieving a balance between performance and sustainability.

Chemical looping gasification (CLG) of alkali lignin with NiFe2O4 oxygen carrier was proposed to achieve hydrogen-rich syngas and realize the resource utilization of papermaking by-product, which exhibits advantages of cheaper oxygen source, lower reaction exergy loss, less tar content, and avoiding inert gas dilution in gas products. The kinetic behavior and reaction performance was evaluated by TG and fixed bed reactor coupled with thermal analysis kinetic of non-isothermal and heterogeneous systems. The results exhibited that the exogenous potassium alkali metal significantly reduced the average reaction activation energy from 182.62 kJ/ mol to 142.16 kJ/mol and the CLG process conformed to the model of random nucleation and nuclear growth (n = 4). The presence of alkali metal and water molecules with the increasing temperature played a positive role in enhancing the CLG reaction process, adjusting the H2/CO ratio and improving the syngas yield and carbon conversion efficiency. Hydrogen-rich synthesis gas with H2 composition 57.67 %, LHV 13.28 MJ/m3, syngas yields 1.99 m3/kg, H2/CO 3.92 and carbon conversion 82.20 % was achieved in CLG of K-AAL with H2O molecular participation. The carbon conversion of K-AAL in CLG process is 28.78 % higher than that of AAL without alkali metal. The reaction path of NiFe2O4 oxygen carrier in CLG process was summarized as: NiFe2O4 -> Fe0.5/ Ni0.5 -> Fe2O3/NiFe2O4. The CLG process is an effective way to prepare the synthesis gas for Fischer-Tropsch synthesis and realize the resource utilization of alkali lignin.