The rapid and sensitive detection of trace antibiotics in environmental and biological samples is crucial for food safety and public health. This study presents a novel electrochemical aptasensor based on a porous covalent organic frameworks/graphene oxide (namely COF/GO) hybrid material for selectively detecting penicillin (PCL). A specific aptamer was immobilized on the modified electrode surface for high-affinity recognition of PCL. The binding event between the aptamer and PCL induces a measurable change in the electrochemical signal, which is quantitatively analyzed using differential pulse voltammetry (DPV). The developed aptasensor demonstrated excellent performance with a wide linear range from 0.01 ng mL− 1 to 10.0 ng mL− 1 and an ultralow detection limit of 2.9 pg mL− 1. The sensor exhibited high selectivity against interfering substances and good stability for storing 8 days. This work highlights the potential of porous COF/GO composite-based electrochemical aptasensors as a powerful tool for real-time monitoring of antibiotic residues in complex matrices.

Conventional hydrophobic membranes often suffer from fouling accumulation due to the absence of effective self-cleaning mechanisms, thereby hindering their long-term operational stability and recyclability. In this study, a polyacrylonitrile (PAN)-based composite nanofiber membrane with a hierarchical micro-nano surface structure was fabricated by combining the in-situ growth of TiO2 with an optimization of octadecyltrimethoxysilane (OTMS) coating morphology. Benefiting from the unique hierarchical morphology of micron-scale flower clusters and nano-protrusions, coupled with the synergistic effect of photocatalyst TiO2 and the superhydrophobic layer OTMS, the resulting nanofiber membrane (PAN/TiO2/OTMS) exhibited outstanding dual-functional properties of superhydrophobicity (water contact angle >154 degrees, sliding angle <5 degrees) and photocatalytic activity (a degradation efficiency of 99 % for methylene blue within 150 min). Moreover, the PAN/TiO2/OTMS nanofiber membrane demonstrated favorable demulsification capability in water-in-oil emulsions, with an oil permeation flux of 2388 L m(-2)& centerdot;h(-1) and a water separation efficiency of 99.9 %. More importantly, owing to dual self-cleaning mechanisms of physical superhydrophobicity and chemical photocatalysis, the as-prepared PAN/TiO2/OTMS exhibited a favorable antifouling and regeneration performance, demonstrating the oil flux recovery above 83 % and the irreversible fouling ratio below 17 % after multiple operation cycles. This study offers a practical strategy for the rational development of advanced membranes that integrate synergistic physical and chemical self-cleaning properties.

Hydrogen sulfide (H2S) is a crucial endogenous gas transmitter for the evaluation of food spoilage and disease diagnosis. Thus, we have effectively prepared a novel Aggregation-Induced Emission (AIE) probe EHAT, which displayed a obvious fluorescence color change after the addition of H2S (from orangered to green), suggesting that probe EHAT can identify H2S with the naked eye and the detection limit was calculated to be 1.5 × 10−7 M for H2S. The probe EHAT-based test strip was also developed to conveniently detect H2S gas generated during food spoilage. Moreover, the probe EHAT were successfully utilized to image endogenous and exogenous H2S in live cells.

Hydrogen-bonded organic frameworks (HOFs) have emerged as promising porous materials for membrane fabrication. In this study, HOF-GS-10, synthesized from the dual ligands 1,5-naphthalenedisulfonic acid (providing sulfonic acid groups, -SO3H) and guanidine hydrochloride (providing guanidinium cations, -C (NH2)+3 ), was selected as a nanofiller to prepare high-performance thin-film nanocomposite (TFN) membranes for reverse osmosis (RO) desalination. The HOF-GS-10 nanoparticles were uniformly incorporated into the poly-amide (PA) active separation layer on a polysulfone (PSF) substrate via interfacial polymerization. Benefiting from the synergistic effects of the ultrathin PA layer, the porous structure of HOF-GS-10, and the strong hydrophilicity of the sulfonic acid groups, the resulting TFN membrane exhibited an average water permeability of 74.6 L center dot m-2 center dot h-1 center dot MPa-1, which is 260% of that the pristine thin-film composite (TFC) membrane that of the pristine thin-film composite (TFC) membrane, while maintaining a high NaCl rejection rate of 99.3%. Moreover, the HOF-modified TFN membrane demonstrated high desalination performance using natural seawater, achieving an average water permeability of 16.7 L center dot m-2 center dot h-1 center dot MPa-1. In addition, the membrane showed excellent antifouling performance against 500 ppm humic acid (HA), with a water flux recovery rate of 95.2%, and exhibited stable operation over 48 h. Molecular dynamics (MD) simulations revealed that the incorporation of hydrophilic HOF-GS-10 into the PA layer enhances water permeability by increasing the number of hydrogen-bonding sites available for water transport. This study not only proposes a novel strategy for developing highperformance RO membranes but also opens a new avenue for the application of HOF nanomaterials in advanced water treatment applications.

Hydrogen sulfide (H2S) and biogenic amines (BAs) are naturally generated from foods that adversely affect human health. The very close structural similarities between cysteine and homocysteine present a great challenge to achieve their selective detection using regular fluorescent probes, limiting the biological and pathological studies of these two amino thiols. In this work, we have developed a novel ratiometric AIE probe named MTMC for the visual discrimination detection of H2S and BAs. Probe MTMC displayed a remarkable fluorescence color change after the addition of H2S (from red to yellow) and BAs (from red to green), suggesting that MTMC can identify two analytes with the naked eye. Also, NMR, HRMS and DFT calculation confirmed the different sensing mechanism of probe MTMC for H2S and BAs. Also, we successfully prepared MTMC test strips and was applied for real-time monitoring of H2S gas and BAs gas released during food spoilage. Importantly, MTMC demonstrated the ability in the detection of H2S in living cells by ratiometric fluorescence singal and effectively accumulate in the tumor region and could as a powerful tool in early clinical diagnosis.

Herein, we explore the development of three copper(II) Schiff base complexes (Cu-SBC, C1-C3) aimed at inhibiting urease (UA), achieved through the thoughtful design of ligands. By integrating a fluorinated Schiff base ligand (SBL) with auxiliary ligands-namely, 2-methylimidazole, 2-ethylimidazole, and 6,6 '-dimethyl-2,2 ' bipyridine-this research systematically examines the impact of steric factors on the inhibition of the UA enzyme. The synthesized complexes underwent comprehensive characterization, including crystallographic analysis. The three synthesized Cu(II) complexes exhibit two distinct coordination geometries dictated by their auxiliary ligands. C1 and C2 display four-coordinate distorted square planar geometries, while C3 adopts a fivecoordinate distorted square pyramidal configuration. The biological evaluation revealed that C1 demonstrated a markedly enhanced UA inhibitory activity compared to the standard reference acetohydroxamic acid (IC50: 6.12 +/- 0.44 vs. 27.73 +/- 2.93 mu M). Computational methodologies were employed to complement the experimental investigations, elucidating the molecular underpinnings of the observed activity disparities among the complexes. Consequently, the structure-activity relationship analysis indicates that steric hindrance is crucial in modulating the UA inhibitory activity, providing important perspectives for the development of new UA inhibitors and their potential uses in biomedicine.

Two mononuclear Copper(II) complexes, identified as [Cu(C10H8NO4F)(C6H7N)] (C1) and [Cu(C10H8NO4F)(C12H8N2)]H2OCH3OH (C2), incorporating a tridentate Schiff-base ligand with an ONO coordination (C10H8NO4F = 5-fluoro-2-hydroxybenzylidene-L-serine) and two unique auxiliary ligands (C6H7N = 4-methylpyridine and C12H8N2 = 1,10-phenanthroline) were developed and detailed structurally. Density functional theory (DFT) evaluations of these complexes employed Becke's three-parameter hybrid (B3LYP) approach within the Gaussian 16 computational package. The outcomes from computational analysis corresponded with experimental data. Additionally, the inhibition capabilities of complexes C1 and C2 were evaluated in vitro targeting jack bean urease. Simultaneously, molecular docking was utilized to determine potential binding interactions. Experimental results and docking analyses showed that C1 had considerable inhibitory strength (IC50 = 2.44 +/- 0.15 mu M) relative to the benchmark control, acetohydroxamic acid (IC50 = 27.73 +/- 2.93 mu M). Furthermore, a 100-ns molecular dynamics assessment was performed to examine the interaction stability of urease with C1 and C2, using the Desmond 2021 tool from Schr & ouml;dinger. The correlation between structural configurations and inhibition efficacy was further explored through molecular docking, density functional theory analysis, and molecular dynamics evaluations.

Traditional photoelectrochemical (PEC) sensors are limited by bulky electrochemical workstations and high-energy light sources, thus limiting their practical applications. In this study, the photothermal effect of iron single-atom materials (Fe-PNC), pyroelectric effect of Yb-doped Bi2S3 (Yb-Bi2S3), and electrochromic effect of polyaniline (PANI) were innovatively combined to construct a dual-signal portable PEC sensing platform without the need of workstation. Specifically, we designed ITO electrode region: Yb-Bi2S3 nanorods were modified in the photothermal region, and PANI was electrodeposited in the discolored region. The Fe-PNC was introduced into the photothermal region through target-aptamer (Apt) sandwich strategy. Under the irradiation of 808 nm light, Fe-PNC converts light energy into heat energy, causing the temperature in the photothermal region to rise rapidly, thereby enhancing the pyroelectric effect of Yb-Bi2S3 and promoting carrier separation, so a large number of generated pyroelectric electrons migrate to the discolored region, and they trigger the PANI's reduction color-changing reaction (blue to green), thus achieving dual signal output of temperature and color. Based on this, we have successfully achieved highly sensitive and selective detection of enrofloxacin (ENR), which has the advantages of rapid response and intuitive reading. This design not only overcomes the problem of insufficient photogenerated carriers caused by the low energy of near-infrared (NIR) light, but more importantly, uses temperature and color changes to replace the traditional current signal detection, enabling the PEC sensor free of the electrochemical workstation. This research provides new ideas for the development of portable and low-cost PEC sensors.

Covalent organic frameworks (COFs), an emerging class of crystalline porous materials, exhibit significant potential for constructing electrochemical aptasensors to detect trace antibiotics. This potential stems from their high surface areas, excellent stability, and abundant functional sites. In this study, a Pd@COF nanocomposite was successfully synthesized to anchor aptamers. The resulting electrochemical aptasensor demonstrated sensitive quantitative detection of penicillin (PCL) across a broad concentration range (1.0 x 10(-3)-5.0 x 10(-1) ng mL(-1)) with an exceptionally low detection limit (similar to 0.27 pg mL(-1)). Critically, this Pd@COF-based aptasensor proved effective for quantifying varying concentrations of PCL in real milk samples. Therefore, this work not only delivers a highly sensitive electrochemical aptasensor for PCL detection but also expands the application scope of metal@COF nanocomposites within the electrochemical biosensing field.

In this work, we developed a fluorescence probe HCPM with AIE effect. The probe HCPM in solid state showed obvious fluorescence colormetric response from orange-red to green for cadaverine vapor with high selectivity and could quantitative detect cadaverine vapor and a visual detection platform was constructed by combining it with a smartphone. Also, the probe HCPM exhibited significant fluorescence colormetric responses for 12 BAs and could detect the different concentrations of cadaverine in EtOH/H2O (1/9, v/v, pH = 7.4) solution. Moreover, the probe HCPM was loaded on the test paper and silica gel plate as sensing label, which could be used to visual detect the freshness of pork and shrimp.

Developing stable sensing materials for the selective detection of phenylglyoxylic acid (PGA) in biological samples is highly important for the early diagnosis and treatment of various diseases. In this work, a Zn(II)-based coordination polymer (CP), {[Zn(L)(bibp)]·bibp·2H2O}n (1) (H2L = 2,6-di(4-carboxylphenyl)-4-(4-(triazol-1-ylphenyl))pyridine and bibp = 4,4'-bis(imidazolyl)biphenyl), with good chemical and thermal stabilities was solvothermally synthesized. It showed an excellent fluorescence turn-off response capability for the detection of the styrene biomarker PGA with outstanding sensitivity, selectivity, recoverability and anti-interference ability. Moreover, experimental and DFT calculations suggested that the mechanism of fluorescence quenching could be attributed to the synergistic effect of the internal filter effect (IFE) and photo-induced electron transfer (PET) process between the complex and PGA.

In this work, a new dual-signal fluorescence strategy based on nano-gold molecular beacon (MB) and in-situ generated silver nano-clusters (NCs) coupled with multiple amplification technique was developed for sensitive detection of miRNA (let-7b). miRNA can recognize both hairpin probe (HP) and auxiliary DNA, inducing dual-cycle amplification-process to release plenty of DNA S2. As the report probe carboxyfluorescein (FAM) was modified on Au nanoparticles (AuNPs), the fluorescent signal was quenched due to the fluorescence resonance energy transfer (FRET). After DNA S2 opened the hairpin structure of the report probe, the fluorescence was recovered for target detection. Furthermore, the amplification product S2 can also trigger hybrid chain reaction (HCR) on silicon spheres, which opened numerous hairpin structure (HP1 and HP2) and exposed C-rich sequences, so abundant nanosilver clusters can be in situ synthesized for fluorescence detection of target. This method combines multiple amplification technique with two fluorescent probes to achieve simple, rapid and sensitive double-detection of target, which greatly improves the accuracy of bioanalysis and has great application potential in clinical detection.

Covalent organic frameworks (COFs) show a great potential application in the field of constructing electrochemical aptasensors due to their high specific surface area, abundant pores, and good stability. Crystallinity (i.e., orderliness) is directly related to the structural characteristics of porous frameworks and affects their sensing performance. However, few reports focus on the influence of crystallinity on electrocatalytic aptasensing performance. This work develops copper porphyrin-based COFs with different crystallinity to fabricate electrochemical aptasensors for detecting penicillin. The research results indicate that highly ordered COF has higher specific surface area and ordered pores, which can significantly improve sensing performance.

In this work, an easy prepared solid fluorescent sensor 3-(benzo[d]thiazol-2-yl)-1-hydroxy-4-oxo-3,4-dihydrophthalazine-6-carboxylic acid (BPCA) was designed and synthesized and the structure was proved by IR, UV-Vis, NMR, HRMS and elemental analysis, which displayed high selectivity and sensitivity for fluorescence colormetric from green to blue sensing 1, 4-dioxane in water, and the detection limit was obtained 0.009

In order to develop high-performance supercapacitor electrode materials, a two-step method of hydrothermal in-situ synthesis and high-temperature activated pore creation was used to realize the highly dispersed loading of nickel oxide nanoparticles (NiO) on mango kernel-based activated carbon (AC) with a high specific surface area for the preparation of NiO/AC composites. Electrochemical tests showed that the NiO/AC achieved a specific capacitance of 226.5 F g-1 at a current density of 0.2 A g-1, demonstrating excellent multiplicative performance and cycling stability (95.8% capacitance retention after 10,000 charge/discharge cycles). This performance stems from the stabilized multilayered pore structure that reduces the particle size of NiO and builds fast ion/electron transport channels to realize the dual advantages of double layer capacitance and pseudocapacitance. The present synthesis strategy is universal (compatible with multifunctional porous carbon precursors and metal oxides) and can provide new ideas for the design of high-performance supercapacitor electrodes.

Metal-organic frameworks (MOFs), as a class of crystalline organic-inorganic hybrid materials, have demonstrated excellent performance in many fields, resulting in attracting more and more attention. Recently, MOFs have been widely used as functional materials to immobilize aptamers via various interaction forces. The MOF-based aptasensors exhibit outstanding sensing performance, including high sensitivity, excellent selectivity, and good designability, by utilizing the advantages of MOFs and aptamers. Developing MOF-based aptasensors is gradually becoming one of the important research hotspots. Herein, a comprehensive review of aptasensors based on MOFs is provided to summarize recent advancements in this field. Some representative examples are discussed in detail. Furthermore, opportunities and challenges in this field are proposed in this review.

Traditional oil/water emulsion separation membranes often fail to maintain long-term stability and regeneration due to inadequate fouling resistance and low self-cleaning efficiency in practical applications. This study developed a superhydrophilic nanofiber membrane with a micro/nanolayer architecture and piezoelectric photocatalytic properties by combining polyacrylonitrile (PAN), polyethyleneimine (PEI), and silver-modified barium titanate (Ag-DBT). This membrane can effectively separate oils and dyes from complex emulsions, demonstrating high water permeation flux of 2492 L.m(-2).h(-1), along with exceptional oil separation efficiency (similar to 99 %) and dye adsorption (similar to 99 %). In addition, the PAN-PEI/Ag-DBT membrane demonstrated an ultra-high degradation efficiency of approximately 99 % for methyl blue (MB) within 90 min. Notably, owing to the piezoelectric photocatalytic properties of Ag-DBT, the PAN-PEI/Ag-DBT nanofiber membrane maintained exceptional self-cleaning performance even after high contamination. To assess the self-cleaning performance and cycling stability of the PAN-PEI/Ag-DBT membrane, we conducted cyclic recovery experiments across three conditions: oil-in-water emulsions, dye-water solutions, and oil-in-dye-water emulsions. In the first three self-cleaning cycles, the self-cleaning membrane demonstrated water flux recovery rates that exceeded 90 % and irreversible fouling rates that were below 10 %. This research provides new insights into the advancement of multifunctional self-cleaning membranes.

In this study, we present a dimensional reduction strategy to enhance the fluorescence sensing properties of metal-organic frameworks (MOFs). By using racemic 2-methylpiperazine (S/R-MPZ) and enantiopure S-MPZ as ligands, we synthesized a two-dimensional (2D) MOF ([Cu2I2(S/R-MPZ)]) (1) and a 3D MOF ([Cu2I2(S-MPZ)]center dot H2O) (1 ') based on the same Cu4I4 cluster. Structural analysis revealed that the spatial arrangement of methyl groups on the ligands introduces steric effects, which dictate the extension patterns of both ligands and clusters. These steric variations account for the dimensional discrepancy between the 2D MOF (1) and its 3D counterpart (1 '). Both compounds exhibit strong photoluminescence at room temperature. Notably, due to weak interlayer interactions, 1 can be easily exfoliated into ultrathin nanosheets compared to 1 '. This facilitates the fabrication of test papers with superior fluorescence performance and significantly enhanced sensing capabilities for nitrobenzene.

A novel dendritic DNA-quantum dot (QD) electrochemiluminescence (ECL) probe was developed and an ECL biosensor constructed for sensitive detection of Hg2+ in water samples by combining with enzyme-assisted multiple cycle amplification strategy. Firstly, the Y-shaped structure was formed based on the Hg2+-induced enzymatic cycle amplification technique, which improved the cutting efficiency and realized the double-amplified DNA product. Moreover, a unique dendritic DNA nanostructure loading numerous QDs was constructed, which can greatly amplify the ECL signal. After the dendritic DNA signal probe was connected to the CNT/gold nanocomposites/electrode by DNA products, the ECL biosensor was constructed for sensitive detection of Hg2+. The proposed dendritic DNA probe opens new ECL application of quantum dots. The smart design of Y-structure coupled with multiple amplification strategy greatly improves detection accuracy and sensitivity; thus, the biosensor not only can detect Hg2+ in water samples, but also has a good application prospect for other targets in environmental analysis.