To achieve highly sensitive and reliable detection of pivotal cancer diagnostic biomarkers like miRNA, and to develop a novel core-satellite assembly strategy for SERS sensing platforms with high "hot spot" density, this study introduces an innovative approach. We integrate enzyme-free, isothermal Catalytic Hairpin Assembly (CHA) and Hybridization Chain Reaction (HCR) in a cascaded manner to construct multi-layered "core-satellite" nanostructures. CHA enables specific target recognition and initial signal amplification, while subsequent cascaded HCR generates long dsDNA scaffolds, facilitating the assembly of multiple satellite nanoparticle layers around a central core. This design significantly increases the number and density of SERS "hot spots," leading to substantially enhanced signals. The strategy was successfully applied for the highly sensitive detection of miRNA-21. Furthermore, a dual-modal biosensing platform combining fluorescence and SERS outputs was developed, improving detection reliability and accuracy. This work presents a robust methodology for precise miRNA analysis and advances the development of high-performance, multi-layered core-satellite nanostructures for broader biosensing applications.

ABSTRACT The inherent viscoelastic behaviors of dielectric elastomers (DEs), such as creep and hysteresis, are important for their long‐term service stability and energy efficiency in cyclic applications. In this work, a constrained interface between dielectric filler and silicone rubber matrix was constructed by modifying nano‐silica surface with vinylmethyl dimethoxysilane (VMDMS). By the co‐crosslinking reaction among the vinyl groups of modified nano‐silica and polymethylvinylsiloxane (PMVS) matrix, the polymer chain mobility was restricted and the filler dispersion was improved. The as‐obtained VMDMS@SiO 2 /PMVS nanocomposites exhibited remarkably enhanced compressive creep as low as 0.25%, which was 86% lower than that of SiO 2 /PMVS nanocomposite. Furthermore, the constrained interface also provided excellent dielectric stability after creep and minimized hysteresis loss during cyclic loading. This study presents an effective interfacial design strategy for developing durable and reliable DEs with suppressed viscoelasticity, which has the potential for applications in soft robotics and energy harvesting.

The encapsulation of phase change materials within a mechanically robust matrix is a distinctive strategy for obtaining monolithic phase change composites that can be directly shaped and applied for thermal management. Herein, based on the construction of a stable medium internal phase emulsion (MIPE), a monolithic closed-cell foam that could serve as an effective form-stable phase change material (MF-PCM) was fabricated by a one-step emulsion templating approach. Firstly, the stability of MIPE was studied in detail. It was found that the introduction of nano-silica as Pickering emulsifier and carboxymethylcellulose sodium (CMC-Na) as the thickener of the continuous phase constituted the key factors for keeping MIPE stable, and then a closed-cell polymer foam (polyMIPE) could be obtained. Subsequently, when the phase change material (PCM) of n-octadecane (OD) was introduced as the dispersed phase of MIPE, a monolithic foam that could be applied on form-stable phase change energy storage (MF-PCM) was fabricated by a facile one-step emulsion templating strategy. Furthermore, the fatty chain modified carbon nanotubes (CNTs-ODA) were added to ensure the cyclic stability and improve the thermal conductivity of MF-PCM. Finally, the CNTs@MF-PCM with 40% OD and 0.15 wt% CNTs-ODA exhibited high enthalpy (211.15 J/g) and stable cyclic performance for 20 heating and cooling cycles. The preparation approach of monolithic closed-cell foam by medium internal phase emulsion template provides a facile construction strategy for thermal energy management and storage.

Heme is an essential cofactor involved in diverse cellular processes and is an important target for microbial biosynthesis. However, engineering microbial heme production remains challenging due to the requirement for coordinated activity of multiple pathway enzymes and the lack of scalable strategies for enzyme-level screening. In this study, we developed a growth-coupled screening system in Corynebacterium glutamicum by establishing a ChrSA-based heme biosensor derived from the native heme-responsive two-component system, which directly converts intracellular heme levels into a selectable growth phenotype. Using this biosensor-enabled system, random mutagenesis libraries were constructed for four key enzymes of the coproporphyrin-dependent (CPD) heme biosynthesis pathway, and improved variants were identified through biosensor-guided selection. The selected variants were subsequently validated by chromosomal allelic replacement, resulting in an overall increase in heme production of approximately 38.9% and a final titer of 308.7 mg/L under native, single-copy regulation. Sequence and structural analyses indicated that the beneficial substitutions were predominantly located outside catalytic residues, suggesting that changes in enzyme stability and conformational properties contributed to the enhanced heme biosynthesis. This work established a heme biosensor-guided strategy for enzyme variant screening in tightly coupled metabolic pathways and provided a practical systems-level approach for microbial heme pathway engineering.

The development of highly sensitive and reliable biosensors is essential for the early diagnosis and therapeutic monitoring of cancer. Herein, we report a dual-mode fluorescence-colorimetric biosensing platform for the ultrasensitive detection of miRNA-21, integrating AuNP-supported dual-stage rolling circle amplification (RCA) with an RCA-generated multipedal binding-and-cleavage mechanism. The sensing hierarchy is initiated by target-dependent activation of the primary RCA on the gold nanoparticle (AuNP) surface, producing long DNA strands with multiple repeated recognition domains that function as numerous walker "legs" and form a DNA-rich nanogel matrix. Through these repeated domains, the RCA-generated multipedal walker repeatedly and multivalently binds fluorophore-labeled hairpin substrates on the AuNP surface, thereby facilitating APE1-mediated substrate cleavage and fluorescence recovery. The APE1-generated cleavage fragments subsequently initiate the secondary RCA following the addition of the T2 template. The two successive RCA reactions ultimately produce an Au@RCA DNA nanogel containing abundant G-quadruplex/hemin DNAzymes that catalyze a visually detectable color change. By integrating the multipedal walker-mediated multivalent binding-and-cleavage process with dual-stage RCA, the platform enables dual-mode fluorescence-colorimetric detection with efficient signal amplification and low background, achieving limits of detection of 9.854 and 790 fM for the fluorescence and colorimetric modes, respectively. Furthermore, the two complementary outputs provide independent signal readouts for cross-validation. The biosensor demonstrated excellent specificity and distinguished the endogenous responses of MCF-7, HeLa, and HEK293T cell lysates. These results support the potential of the platform for ultrasensitive tumor-associated biomarker detection, while the cell-lysate experiments represent a preliminary proof-of-concept evaluation in complex biological matrices.

The development of lightweight and high-strength polymer foams via a cost-effective strategy has been important to advanced structural applications. Herein, a facile approach for fabricating ultrahigh-strength closed-cell polystyrene (PS) foams by medium internal phase emulsion (MIPE) templating is presented, in which the stable MIPE is obtained through a prepolymerization strategy. The critical roles of internal phase volume fraction, initiator content, surfactant content, and crosslinking degree in determining the porous morphology and resultant mechanical performances are investigated in detail. It is revealed that the synergistic effect of the highly crosslinked polymer matrix and the well-defined closed-cell structure provides exceptional mechanical properties for the foams. The highest compressive strength of 12.2 MPa at the low density of 293 kg & centerdot;m-3 of the obtained PS foam is achieved. In addition, the foam has good thermal stability and a low dielectric constant. As a result, the high-performance closed-cell PS foams prepared by an effective and economical pathway show significant potential as a competitive alternative to conventional high-cost engineering foams in fields such as aerospace and functional structures.

To address background interference and sensitivity limitations in detecting miRNA-21 within complex clinical matrices, an ultrasensitive electrochemical sensing platform was developed by integrating HKUST-1 type Cu-MOF@Au nanozymes with primer exchange reaction (PER) mediated cascade amplification. The Cu-MOF@Au@S1 nanocomposite was synthesized via a solvothermal method followed by a stepwise assembly strategy. By anchoring gold nanoparticles (AuNPs) onto the HKUST-1 framework, the hybrid material synergistically combines high specific surface area and ordered porosity with enhanced conductivity and biocompatibility, providing a providing a suitable scaffold for the high-density immobilization of DNA probe S1. Regarding the sensing mechanism, a double-locked activation strategy was implemented, wherein the protected hairpin (PH) probe is activated only by the combined action of APE1-specific cleavage and miRNA-21 recognition. This event initiates the PER process, generating programmable long-chain DNA with tandem repeats that act as molecular tethers to drive the exponential assembly of functionalized nanozymes onto the electrode surface. This dual-triggering paradigm effectively suppresses non-specific background leakage and minimizes false-positive risks. The proposed sensor exhibited a linear quantitative range of 10–200nM and an experimental limit of detection (LOD) of 5 pM for miRNA-21. Furthermore, the platform demonstrated robust stability and analytical fidelity in cell lysates and serum samples. By integrating nanocatalysis with programmable molecular amplification, this work offers a versatile strategy for developing low-background and high-specificity biosensors for advanced molecular diagnostics.

Adsorbent materials with high adsorption efficiency, good processing stability, and high adsorption rate, are crucial for carbon capture, utilization and storage (CCUS) technology. In this paper, a novel polyethyleneimine (PEI)-embedded porous adsorbent with high amine-content matrix was one-step prepared successfully by a unique high internal phase emulsion (HIPE) polymerization. Firstly, the amphiphilic polyethyleneimine-based carbon nanotubes (CNT-PEI) was synthesized and applied as a Pickering emulsifier, and the interfacial tension was analyzed by a multi-functional tensiometer. Secondly, a large amount of divinylbenzene (DVB) was introduced into the continuous phase of HIPE, and then some mesopores were generated in the framework of the macro-porous polymer, which indicated by specific surface and pore size analyzer and scanning electron microscope (SEM), respectively. Finally, the additional PEI was added into the dispersed phase of HIPE. In such unique HIPE template, PEI was penetrated into the framework and then the porous polymer with high aminecontent matrix was achieved. The morphology, the surface element content and the CO2 adsorption capacity of the obtained porous polymer were characterized by SEM, energy dispersive spectrometry (EDS), and the gas sorption analyzer. When the obtained porous polymer was applied as CO2 adsorbent, the better comprehensive adsorption performance, including high CO2 adsorption capacity of 2.87 mmol/g, fast adsorption kinetics, the isosteric heat of adsorption (Qst) range of 65-68 kJ/mol, exceptional CO2/N2 selectivity with a separation factor up to 118, and stable adsorption-desorption cycles, was exhibited. The superior CO2 adsorption capacity and adsorption kinetics make it a promising candidate in practical CO2 adsorption application.

The escalating global cancer burden necessitates the development of precise tumor-specific microRNA (miRNA) detection strategies. However, the low-abundance, short-length, and high-sequence homology of miRNAs significantly hinder their accurate detection. Moreover, growing evidence of miRNA codysregulation in tumorigenesis underscores the diagnostic advantage of multiplexed analysis over single-marker approaches. Here, we present a novel bipedal DNA walker-based biosensor (BDWA) assembled on gold nanoparticles for the simultaneous detection of dual-miRNA targets. This system uniquely integrates dual-miRNA responsiveness with tumor-endogenous enzyme-driven signal amplification operating within a triple-input orthogonal AND-logic gate framework to enhance diagnostic specificity. Specifically, the concurrent presence of miR-21 and miR-155 displaces blocking strands to activate the walker, while the tumor-associated endonuclease APE1 serves as an intracellular trigger that propels the walker along engineered hairpin tracks (H1) on AuNPs. APE1-mediated cleavage of abasic (AP) sites results in the release and amplification of fluorescence signals initiated by the dual-targets. The bipedal architecture of the walker ensures a high processivity and efficient signal amplification. Critically, this design produces output signals only when all three inputs─miR-21, miR-155, and APE1─are present, thereby minimizing background interference and false positives. The BDWA system demonstrates high sensitivity and specificity for dual-miRNA detection in tumor cell lysates and intracellular imaging, offering a robust, tumor-activated, and programmable molecular platform for next-generation cancer diagnostics.

To achieve precise diagnosis of tumor cells, designing nucleic acid amplification circuits with intelligent multi-switch responsiveness for the specific and sensitive detection of miRNA within tumor cells is an important strategy. Here, we developed a dual-switch fluorescence biosensor that integrates a two-step cascade signal amplification circuit of an entropy-driven circuit (EDC) and DNA walkers onto gold nanoparticles for highly sensitive and quantitative detection of target miRNA in tumor cells. The dual switches that trigger the fluorescence signal are miRNA and the APE1 enzyme, both of which are upregulated in tumor cells. To be specific, the target miRNA21 triggers the upstream EDC, releasing strands that serve as walkers for the downstream circuit. Under the cleavage-driven action of the APE1 enzyme, the walker strands walk along the track strands on the surface of AuNPs, releasing a strong fluorescence signal and presenting good linearity in the target miRNA concentration range of 40 pM-100 nM. This biosensor presents good specificity, strong anti-interference ability against multiple RNAs and enzymes and can effectively distinguish cancer cells from normal cell lysates. Overall, this dual-switch fluorescence biosensor provides a precise recognition and efficient amplification strategy for miRNA detection within tumors, indicating its potential for clinical applications in disease diagnosis.

In this study, a novel dual-switch fluorescent biosensor based on a bipedal DNAzyme walker was developed for the highly sensitive detection of the tumour biomarker miRNA-141. By exploiting the typically elevated expression levels of miRNA-141 and apurinic/apyrimidinic endonuclease 1 (APE1) in tumour cells, an endogenous dual-gating system was constructed. The presence of both targets was required to initiate an enzyme-free strand displacement reaction, enabling target recycling and the subsequent release of bipedal DNAzyme walker components (D1/D2), which were efficiently isolated using streptavidin-modified magnetic beads. In the presence of Mg2+, the activated DNAzyme walker specifically cleaved fluorophore-labelled substrate strands on gold nanoparticles (AuNPs). Through repeated "walking-cleavage" cycles, fluorescence signals were progressively restored and amplified. By integrating AuNPs as carriers and magnetic separation technology, a cascade dual-amplification system based on non-enzymatic strand displacement and bipedal DNAzyme walking was established, markedly enhancing the detection sensitivity. The biosensor exhibited dual-switch-specific activation, effectively suppressing interference from non-target RNAs and other nucleases, and maintained a low background signal. It demonstrated excellent discrimination between tumour cells and normal cells, and showed good anti-interference performance in spiked serum samples. This study provides a new strategy for the development of high-precision tumour biomarker detection, offering potential for trace analysis in complex biological samples.

To achieve highly sensitive and reliable detection of apurinic/apyrimidinic endonuclease 1 (APE1), a critical cancer diagnostic biomarker, we designed a DNA walker-based dual-mode biosensor, utilizing cellular endogenous dual enzymes (APE 1 and Flap endonuclease 1 (FEN 1)) to collaborate in activating and propelling DNA walker motion on DNA-functionalized Au nanoparticles. Incorporating both fluorescence and electrochemical detection modes, this system leverages signal amplification from DNA walker movement and cascade amplification through tandem hybridization chain reactions (HCR), achieving highly sensitive detection of APE 1. In the fluorescence mode, continuous DNA walker movement, initiated by APE1 and driven by FEN1, generates a robust signal response within a concentration range of 0.01-500 U mL-1, presenting a good linearity in the concentration range of 0.01-10 U mL-1, with a detection limit of 0.01 U mL-1. In the electrochemical detection module, the cascade upstream DNA walker and downstream HCR dual signal amplification strategy further enhances the sensitivity of APE1 detection, extending the linear range to 0.01-50 U mL-1 and reducing the detection limit to 0.002 U mL-1. Rigorous validation demonstrates the biosensor's specificity and anti-interference capability against multiple enzymes. Moreover, it effectively distinguishes cancer cells from normal cell lysates, exhibiting excellent stability and consistency in the dual-modes. Overall, our findings underscore the efficacy of the developed dual-mode biosensor for detecting APE1 in serum and cell lysates samples, indicating its potential for clinical applications in disease diagnosis.

A high-performance biomass-based adsorption materials could be the promising trend for CO2 capture and storage technology. However, the direct application of biomass-based porous materials as a CO2 adsorbent with enhanced performance is an emerging issue. Herein, a facile synthesis and a biomimetic strategy were combined to prepare amine-functionalized chitosan foam for CO2 capture, and then a porous biomass is achieved for the application on the environment protection field. Firstly, the chitosan foam was synthesized by the emulsion-templating method at room temperature. Depended on stabilizing n-octane in the chitosan hydrogel with Span 80, a tunable three-dimensional network porous structure was obtained. Subsequently, co-deposition with dopamine (DA) and polyethyleneimine (PEI) was applied to load abundant amine content on the surface of chitosan foam and thereby improving CO2 adsorption capacity. Finally, the as-prepared amine-functionalized chitosan foam exhibited the impressive adsorption capacity of 3.59 mmol/g at 333 K and atmospheric pressure, and the better adsorption selectivity and stability. The results extend the preparation approach of biomass porous materials, and also its application in CO2 adsorption technology.

With the rapid development of the application in health-monitors and wearable devices, the demand for the piezoresistive sensors with both high flexibility and high sensitivity has been growing. In this work, a porous carbon nanotubes/polydimethylsiloxane (CNTs/PDMS) composite was prepared by high internal phase emulsion (HIPE) template. The PDMS foam with tens of micrometers of pores offered high flexibility and elasticity. Moreover, guided by cetyltrimethylammonium bromide (CTAB) in HIPE, CNTs were selectively distributed in inner pores' surface of the foam, and then the 3D conductive network was constructed. As a result, the stress of the foam was 107.1 kPa at 60 % compressive strain and the electrical conductivity reached 9.77 x 10(-5) S m(-1), when the volume fraction of CNTs was 1 vol%. Finally, the flexible conductive foam was applied for a piezoresistive sensor. The sensor exhibited a high gauge factor (GF = 24.15) and a wide working range (0 similar to 60 %). Furthermore, the human movements, such as finger bending and walking, were detected by as-prepared piezoresistive sensor, and a good response was obtained.

Since microRNAs (miRNAs) are valuable biomarkers for disease diagnosis and prognosis, the pursuit of enhanced detection sensitivity through signal amplification strategies has emerged as a prominent focus in low-abundance miRNA detection research. DNA walkers, as dynamic DNA nanodevice, have gained significant attention for their applications as signal amplification strategies. To overcome the limitations of unipedal DNA walkers with a restricted signal amplification efficiency, there is a great need for multi-pedal DNA walkers that offer improved walking and signal amplification capabilities. Here, we employed a combination of catalytic hairpin assembly (CHA) and APE1 enzymatic cleavage reactions to construct a tripedal DNA walker, driving its movement to establish a cascade signal amplification system for the electrochemical detection of miRNA-155. The biosensor utilizes tumor cell-endogenous microRNA-155 and APE1 as dual-trigger for DNA walker formation and walking movement, leading to highly efficient and controllable signal amplification. The biosensor exhibited high sensitivity, with a low detection limit of 10 pM for microRNA-155, and successfully differentiated and selectively detected microRNA-155 from other interfering RNAs. Successful detection in 20 % serum samples indicates its potential clinical application. In addition, we harnessed strand displacement reactions to create a gentle yet efficient electrode regeneration strategy, to addresses the time-consuming challenges during electrode modification processes. We have successfully demonstrated the stability of current signals even after multiple cycles of electrode regeneration. This study showcased the high-efficiency amplification potential of multi-pedal DNA walkers and the effectiveness and versatility of strand displacement in biosensing applications. It opens a promising path for developing regenerable electrochemical biosensors. This regenerable strategy for electrochemical biosensors is both label-free and cost-effective, and holds promise for detecting various disease-related RNA targets beyond its current application.

Biomolecule-functionalized nanoparticles represent a type of promising biomaterials in biomedical applications owing to their excellent biocompatibility and versatility. DNA-based reactions on nanoparticles have enabled emerging applications including intelligent biosensors, drug delivery, and biomimetic devices. Among the reactions, strand hybridization is the critical step to control the sensitivity and specificity of biosensing, and the efficiency of drug delivery. However, a comprehensive understanding of DNA hybridization on nanoparticles is still lacking, which may differ from the process in homogeneous solutions. To address this limitation, coarse-grained model-based molecular dynamic simulation is harnessed to disclose the critical factors involved in intermolecular hybridization. Based on simulation guidance, DNA walker-based smart theranostic platform (DWTP) based on "on-particle" hybridization is developed, showing excellent consistency with simulation. DWTP is successfully applied for highly sensitive miRNA 21 detection and tumor-specific miRNA 21 imaging, driven by tumor-endogenous APE 1 enzyme. It enables the precise release of antisense oligonucleotide triggered by tumor-endogenous dual-switch miRNA 21 and APE 1, facilitating effective gene silencing therapy with high biosafety. The simulation of "on-particle" DNA hybridization has improved the corresponding biosensing performance and the release efficiency of therapeutic agents, representing a conceptually new approach for DNA-based device design. Molecular dynamic simulations are used to uncover critical factors in intermolecular hybridization and successfully developed a DNA walker-based smart theranostic platform, which exhibits good efficacy and excellent consistency with simulations. image

Amine-functionalized adsorbents have become one of the most promising capture technologies for greenhouse gas mitigation. However, developing cost-effective adsorbents with high adsorption capacity and superior cyclic stability via temperature swing adsorption remains difficult. Herein, sandwich-like polyethyleneimine (PEI)-impregnated porous carbon-silica sheets derived from vermiculite (AEVCP) adsorbents were successfully synthesized via porous carbon network confined within acid activated expanded vermiculite derived silica (AEV) sheets and interlayer amine-functionalization with PEI impregnation. The effect of adsorption temperature on CO2 adsorption performances, adsorption/desorption kinetics and thermodynamics for AEVCP adsorbents were specifically discussed. The optimal AEVCP50 adsorbent possessed a large CO2 uptake of 1.84 mmol/g at 75 degree celsius in 60 vol% CO2/40 vol% N-2 and superior cyclic stability with 7.6 % decay after 10 cycles, due to the hierarchical porous structure and high thermal conductivity of porous carbon-silica sheets derived from vermiculite (AEVC) support. The unique sandwich-like features of AEVC support are favorable for the high amine loading, rapid CO2 diffusion and efficient capture. The interlayer carbon implantation and amine-functionalization with strong interlayer spatial confinement effect, can suppress the formation of urea linkages, avoid the persistent over-heating and excess amine agglomeration, and enhance the gas diffusion and thermal transfer during the adsorption isobar process, which ultimately lead to superior adsorption capability and cyclic stability for CO2 capture. This design approach of cost-effective adsorbents derived from natural minerals provides a new avenue for practical CO2 capture and separation processes.

DNA walker has been widely used in various types of biosensors for signal-amplification detection of low abundance analytes. However, the usual design of unipedal walker provides limited signal amplification effect with poor sensitivity. Here, we designed an electrochemical biosensor based on bipedal DNA walker allowing for highly sensitive detection of apurinic/apyrimidinic endonuclease 1 (APE 1), a significant base excision repair enzyme, which is over-expressed in multiple cancer cells emerging as a promising biomarker for cancer di-agnostics. The bipedal DNA walker can be released after APE1 cleaving apurinic/apyrimidinic (AP) sites , then perform the catalytic hairpin assembly (CHA) process, triggering the downstream hybridization chain re-action (HCR) to achieve a dual-amplified current signal. This bipedal walker presents dramatically increased catalytic efficiency in the upstream CHA process, , finally contributes almost 5 times synergistic enhanced current signal compared to unipedal walker. We successfully realized the highly sensitive detection of APE 1 with a wide linear range from 0.001 U mL-1 to 1 U mL-1 reaching a detection limit of 0.001 U mL-1. This biosensor showed good specificity in discrimination of APE1 from other interfering enzymes. It was successfully applied to investigate APE 1 expression level in cell lysate, demonstrating its potential diagnostics applications.

A cascade signal-amplified fluorescent biosensor was developed for miRNA-21 detection by combining APE1 enzyme-assisted target recycling and rolling circle amplification strategy. A key feature of this biosensor is its dual-trigger mechanism, utilizing both tumor-endogenous miRNA-21 and the APE1 enzyme in the initial amplification step, followed by a second rolling circle amplification reaction. This dual signal amplification cascade significantly enhanced sensitivity, achieving a detection limit of 3.33 pM. Furthermore, this biosensor exhibited excellent specificity and resistance to interference, allowing it to effectively distinguish and detect the target miRNA-21 in the presence of multiple interfering miRNAs. Moreover, the biosensor maintained its robust detection capabilities in a 10% serum environment, demonstrating its potential for clinical disease diagnosis applications.