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Pursuing nanomaterials with high fluorescence quantum yields is of great significance in the fields of bioimaging, medical diagnosis, and food safety monitoring. This work reports on orange-emitting aggregation-induced emission (AIE) copper nanoclusters (Cu NCs) integrated with blue-emitting nitrogen-doped carbon dots (N-CDs), which enables highly sensitive detection of S^2- and Zn²⁺ ions through an off-on ratiometric fluorescence method. The highly emissive Cu NCs was doped by Ce³⁺ with a high quantum yield of 51.30 % in aqueous solution. The S^2- can induce fluorescence quenching of AIE Cu NCs/N-CDs from orange to blue, while Zn²⁺ can restore the orange fluorescence. The probe provided linear detection ranges of 0.5-170 μM for S^2- and 0.05-200 μM for Zn²⁺, with detection limits of 0.17 μM and 0.02 μM, respectively. Moreover, a smartphone assistant ratiometric fluorescent test strips were developed for the rapid and visual detection of S^2- and Zn²⁺. The AIE Cu NCs/N-CDs probe exhibited diverse fluorescence color responses, high fluorescence stability, and low cytotoxicity. The ratiometric system was successfully applied to the detection of S^2- and Zn²⁺ in real water samples as well as in cellular and living imaging, demonstrating its potential in biochemical analysis and food safety monitoring.

Porous carbons with large surface area (>3000 m²/g) and heteroatom dopants have shown great promise as electrode materials for zinc ion hybrid capacitors. Centralized mesopores are effective to accelerate kinetics, and edge nitrogen can efficiently enhance pseudocapacitive capability. It is a great challenge to engineer centralized mesopores and edge nitrogen in large-surface-area porous carbons. Herein, a strategy of melamine-boosted K₂CO₃ activation is proposed to prepare edge-nitrogen-doped hierarchical porous carbons (ENHPCs). KOCN generated by K₂CO₃ reacting cyano groups (-CN) couples with K₂CO₃ activation engineers large-surface-area porous carbon. KCN in-situ generated by KOCN etching carbon atoms plays a template role in constructing centralized mesopores. Edge-nitrogen skeleton is formed by g-C₃N₄ losing -CN, and then in-situ integrated into porous carbon skeleton. The efficiency of melamine-boosted K₂CO₃ activation reaches the highest at a melamine/lignin mass ratio of 0.5, where the optimized ENHPCs (ENHPC-0.5) have a large surface area of 3122 m²/g, a mesopore architecture (2.8 nm) with a mesoporosity of 60.5 % and a moderate edge-N content of 1.9 at.%. ENHPC-0.5 cathode displays a high capacitance of 350F/g at 0.1 A/g, an excellent rate capability of 129F/g at 20 A/g and a robust cycling life. This work provides a novel strategy to prepare heteroatom-doped high-surface-area porous carbons for zinc ion hybrid capacitors.

Modern microelectronics industries urgently require dielectric materials with low thermal expansion coefficients, low dielectric constants, and minimal dielectric loss. However, the design principles of materials with low dielectric constants and low thermal expansion are contradictory. In this study, a new diamine monomer containing a dibenzocyclooctadiene unit (DBCOD-NH₂) was designed and synthesized, which was subsequently polymerized with high fluorine content 4,4'-hexafluoroisopr-opylidene diphthalic anhydride and 4,4'-diamino-2,2'-bis(trifleoromethyl)biphenyl to obtain a series of fluorinated polyimides (PIs). Due to the unique conformational transition of the eight-membered carbon ring, the resulting PI can reach a low averaging thermal expansion coefficient (CTE) of only 12.27 ppm/K over 5-150 ℃ with a size change rate of only 0.16 %. Surprisingly, the synergistic effect of DBCOD-NH₂ with the other two monomers enhances the dielectric performance of the PIs. At an electric field frequency of 10 MHz, the dielectric constant (D_k) and the dielectric loss (D_f) can be reduced to as low as 2.61 and 0.00194, respectively. The strategy used herein largely tackles the challenge of balancing low D_k with low CTE. Furthermore, these PI films also exhibit good thermal stability (with 5 wt% weight loss temperatures ranging from 453 to 537 ℃ in N₂, and glass transition temperatures of 305-337 ℃) and robust mechanical properties (with a tensile modulus of 1.88-2.29 GPa and an elongation at break of 6.36-8.11 %). The combination of low thermal expansion and excellent dielectric properties renders these PIs highly promising for applications in the microelectronics and telecommunications industries.

The simultaneous generation of hydrogen (H₂) and the oxidative transformation of organic molecules through photocatalytic processes represents a highly promising dual-purpose strategy. This approach obviates the necessity for sacrificial agents while augmenting catalytic efficiency, thereby facilitating the integrated production of high-value chemicals and renewable energy carriers. Polymeric carbon nitride (PCN) has emerged as a leading candidate among coupled photocatalysts. Nevertheless, PCN's efficacy is constrained by the inefficient separation of charges and the functional limitations of its active sites. Herein, the incorporation of P-N₃ groups into PCN introduces active sites with pronounced charge asymmetry, resulting in strong local charge polarization. This asymmetric charge distribution, mediated by the P-N₃ groups, significantly enhances exciton dissociation. Remarkably, the P-N₃-modified narrow-dimensional fragmented carbon nitride (P-CNNS) achieves an 85 % conversion rate for 4-MBA with nearly 100 % selectivity, and a hydrogen evolution rate of 27.9 mmol g^-1 (with Pt as a co-catalyst), representing 6.2 times higher than that of bulk carbon nitride (BCN). The charge-polarized sites facilitate the transfer of electrons, which is a pivotal process in the activation of 4-methoxybenzyl alcohol (4-MBA). Additionally, these sites serve as adsorption sites, facilitating the oxidation of 4-MBA into anisaldehyde (AA). This work underscores the potential of non-metallic site catalysts for a wide range of coupled photocatalytic applications.

An idea of using ion-exchanger salt containing optically active cations to prepare ion-selective membranes is proposed. Although the presence of an ion-exchanger in the composition of neutral ionophore based sensors is necessary, the choice of available salts for cation-selective sensors preparation, is usually limited to sodium or potassium compounds. In this work we propose application of an alternative salt, using a cation optically active both in absorption and emission mode as a mobile one. Thus, coloured ion-selective membranes can be obtained. This in turn opens new possibilities of monitoring the state of the receptor layer as well as allows direct analytical application of ion-selective membranes in simple optical mode with all benefits related to eliminating the necessity of using reference electrodes. As a model system Nile blue derivative of tetrakis[3,5-bis(trifluoromethyl)phenyl]borate ion-exchanger was prepared and used to obtain potassium or calcium selective sensors. Selective exchange of ions between the membrane and solution, leading to an increase in optical signal of the solution, can be used to quantify the presence of analyte ions. Thus the sensor pretreatment process is becoming a source of analytical information. The applicability of this approach was verified in determining the presence of potassium ions in the vast majority of interfering ions, e.g. present as impurities in the reagent grade calcium chloride. The resulting potassium ions contents was well comparable with values obtained in course of ICP-MS approach.

Enzyme immobilization techniques are crucial for enhancing enzyme stability and catalytic efficiency. Traditional methods such as physical adsorption and simple covalent binding often fail to maintain enzyme activity and stability. In this study, an innovative multi-level immobilization strategy was proposed to achieve efficient targeted immobilization of nuclease P1 (NP1) by fine-tuning the surface microenvironment. Molecular simulation results revealed that the distinctive electrostatic distribution and the specific placement of basic amino acids, such as lysine, on the NP1 surface caused dopamine to preferentially adsorb on areas away from NP1's active site. This selective adsorption facilitated the directed immobilization of NP1, while the positively charged environment generated by the co-deposited surface further enhanced NP1's adsorption capacity. This multilevel modification was found to significantly optimize the physicochemical environment of the immobilized surface through surface characterization and enzymatic testing. This strategy greatly improves enzyme activity (3590.0 U/mg), stability, and reusability (70 % after 10 cycles). In particular, NP1 on this surface exhibited an optimal Michaelis constant (K_m) of 34.0 mM and a maximum reaction rate of 5.5 mM min^-1, demonstrating the remarkable effect of the modification strategy in enhancing the enzyme catalytic performance. The present study provides an efficient and stable immobilization platform for enzyme catalytic applications by precisely modulating the surface microenvironment and the oriented immobilization strategy, which has an important potential for practical applications. This stable and reusable NP1 platform allows for efficient DNA/RNA cleavage, facilitating its application in industrial biocatalysis, biomedical enzyme-based processes, and biosensors.

Mercury (II) ions (Hg²⁺) are a significant source of heavy metal contamination in groundwater, posing a serious threat to human health and the environment. Therefore, there is an urgent need for the development of a new detection technique with high sensitivity for monitoring Hg²⁺ in contaminated groundwater. Here, we developed a signal amplifying MOF-based probe (NXS@ZIF-8) for on-site and ultrasensitive dual-channel portable detection of Hg²⁺ in groundwater. The successful grafting of the fluorescent probe (NXS) onto ZIF-8 effectively enhanced the enrichment of the NXS probe, thereby amplifying the detection signal for Hg²⁺. Upon exposure to Hg²⁺, NXS@ZIF-8 quickly emits fluorescent signals, which can be easily detected using portable laser-induced fluorescence spectrometers (LIFs) with a low detection limit of 0.30 ppb. Importantly, the platform enables on-site detection of Hg²⁺ in groundwater samples and direct on-site and in-situ detection of Hg²⁺ in contaminated groundwater, achieving acceptable results. Furthermore, NXS@ZIF-8 was fabricated as a paper-based sensor and integrated into a portable smartphone device for visual detection of Hg²⁺ in contaminated groundwater. This work presents an approach for on-site, in-situ and highly sensitive portable detection of heavy metals in contaminated groundwater, eliminating the need for access to specialized laboratory equipment.

Rational regulation of interface structure in photocatalysts is a promising strategy to improve the photocatalytic performance of carbon dioxide (CO₂) reduction. However, it remains a challenge to modulate the interface structure of multi-component heterojunctions. Herein, a strategy integrating heterojunction with facet engineering is developed to modulate the interface structure of metal-organic frameworks (MOF)-based heterojunctions. A series of core-shell UiO-66 (Zr-MOF)-loaded MIL-125 (Ti-MOF) heterojunctions with exposed specific facets were prepared to enhance the separation efficiency of photogenerated electrons-holes in CO₂ photoreduction. Impressively, MIL-125_to@UiO-66 with exposed {1 1 1} facet exhibits an excellent CO production rate (56.4 μmol g^-1 h^-1) and selectivity (99 %) under visible light irradiation without any photosensitizers/sacrificial agents, being 1.4 and 11.3 times higher than individual MIL-125_to and UiO-66, respectively. The type-II heterojunction significantly enhances the separation of photogenerated electrons-holes in physical space. The photogenerated electrons migrate from Zr in UiO-66 to Ti in MIL-125_to, promoting a spatial synergy between CO₂ reduction on MIL-125_to and H₂O oxidation on UiO-66. Compared with MIL-125_rd@UiO-66 with exposed {1 1 0} facet and MIL-125_ds@UiO-66 with exposed {0 0 1} facet, MIL-125_to@UiO-66 with exposed {1 1 1} facet improves the exposure of surface-active Ti sites, thereby enhancing the adsorption/activation of CO₂ to generate the *COOH intermediate. This work provides an effective strategy for designing MOF-based heterojunction photocatalysts to improve photocatalytic performance.

The limited transport of oxygen at the solid-liquid interface and the poor charge separation efficiency of single catalyst significantly impedes the generation of reactive oxygen species (ROS), thereby weakening the application potential of photocatalytic technology in water pollution control. Herein, a hollow porous photocatalytic aerogel sphere (calcium alginate/cellulose nanofibers (CA/CNF)) loaded BiOBr/Ti₃C₂, combining a favourable mass transfer structure with effective catalytic centers was firstly presented. The floatability and hollow pore structure facilitated rapid O₂ transfer via a triphase interface, thereby promoting the generation of ROS. The oxygen diffusion flux of aerogel spheres' upper surface in triphase system exhibited a 0.151 μmol·(m²·S)^-1 increase compared to that of the diphase one based on Finite element simulation (FEM). Furthermore, owing to the regulation of charge spatial distribution by Schottky junction of BiOBr/Ti₃C₂, internal electric field (IEF) of CA/CNF@BiOBr/Ti₃C₂ achieved 1.8-fold improvement compared with CA/CNF@BiOBr, thus enhancing the separation of photogenerated charges. Accordingly, the degradation efficiency and catalytic rate constant of moxifloxacin (MOX) by CA/CNF@BiOBr/Ti₃C₂ in triphase system have improved by 20.1% and 1.5 times compared to those of diphase system, respectively. Moreover, the potential to mineralize multiple quinolone antibiotics (FQs), high resistance to complex water disturbances and excellent stability were revealed in CA/CNF@BiOBr/Ti₃C₂. Besides, the triphase system based on CA/CNF@BiOBr/Ti₃C₂ confirmed the potential for large-scale water treatment application in 500 mL MOX circular flow, reaching 90% MOX removal within 120 min. This research clarifies the oxygen mass transfer mechanism and pathways to the enhanced ROS production in a triphase system, and provides new insights into designing efficient floatable photocatalyst and adaptive reaction devices for new pollutants remediation.