New Journal of Chemistry最新文献

In this work, we present the first systematic study of a metal coordination compound (MCC) based on nickel and 1,4-dihydroxyanthraquinone (quinizarin) as an OER catalyst. The nickel-quinizarin complex referred to as NiQ was synthesized using a facile solvothermal route and a crystalline product was obtained that exhibited excellent structural integrity. Structural data of the as-prepared crystals were obtained by synchrotron microcrystal X-ray diffraction. In the solid state, the Ni(ii) metal centre existed in a distorted octahedral geometry. The complex is further stabilized in the solid state by π-π-stacking interactions between the anthraquinone rings. The redox features of the complex were analysed through cyclic voltammetry (CV), suggesting the involvement of Ni(ii) metal centres in undergoing an oxidation reaction on the application of an anodic sweep. The electrocatalytic performance of NiQ was evaluated by drop casting NiQ slurry on FTO coated glass plates (NiQ@FTO) directly without needing additional binders or conducting particles and running in 1.0 KOH using a three-electrode system. NiQ@FTO achieved an overpotential as low as 300 mV at 10 mA cm^-2, surpassing those of many previously reported coordination complex-based OER catalysts. Furthermore, it demonstrated excellent stability over prolonged electrolysis with no significant degradation. The present work not only reports a new class of 1,4-dihydoxyanthraquinone based MCCs as highly active and durable OER catalysts but also offers useful insights into the structure activity relationship, which could be beneficial in future electrocatalysis.

Crystalline zinc–flavonoid coordination polymers derived from four flavonoids were synthesized. They display diverse morphologies and long-range order depending on the nature of the ligands. These coordination polymers remained stable above pH 3.5, showed complete ligand recovery under strongly acidic conditions (pH < 1), and exhibited antibiofilm activity against Staphylococcus aureus biofilms with BIC₅₀ values down to 33.25 µg mL⁻¹ (L–Zn).

Reliable surface-enhanced Raman spectroscopy (SERS) analysis of serum remains challenging due to strong matrix interference and the poor stability and reproducibility of conventional solid substrates. Herein, we report a reproducible, liquid-phase, label-free SERS analyzer based on serum-stabilized Pickering emulsions. In this system, intrinsic serum components regulate interfacial assembly and nanoparticle distribution, enabling direct detection of molecular fingerprints in complex serum matrices. By directly using human serum as the aqueous phase and optimizing emulsification conditions with a n-hexadecane–ethanol mixed oil phase, a robust oil-in-water emulsion substrate was rapidly constructed, exhibiting excellent signal uniformity with relative standard deviations below 7%. The Pickering emulsion effectively enriches serum metabolites while minimizing macromolecular background interference, enabling label-free spectral acquisition. Our analysis reveals significant variations in amino acids, glucose, and purine-related metabolites, underscoring the analyzer's sensitivity for metabolic profiling. Multivariate techniques, including principal component analysis and a feedforward neural network, enhance spectral feature extraction and metabolic state classification. This liquid SERS strategy combines high reproducibility, minimal sample pretreatment, and compatibility with data-driven analysis, establishing a versatile tool for serum metabolite fingerprinting and metabolic studies in complex biofluids.

Herein, we report a multifunctional DNA hydrogel (TBDH) platform that integrates the specific detection and efficient inactivation of S. aureus within a single programmable architecture. The platform consists of three core components: an aptamer (Apt) for target recognition, two DNA signaling strands (SA and SB) for fluorescence transduction, and self-assembled antibacterial nanoparticles (TBNPs). Through rational structural integration, these elements are incorporated into a tunable polymeric network, enabling a unified “recognition–reporting–inactivation” function. In the presence of S. aureus, Apt binding triggers hydrogel dissociation, restoring the quenched Cy3 fluorescence and generating a dose-dependent signal with a detection limit of 11 CFU mL⁻¹. Simultaneously, hydrogel collapse induces on-demand release of TBNPs, which exhibit potent antibacterial and anti-biofilm efficacy (>99.9% inactivation) by disrupting bacterial membrane integrity. The TBDH platform demonstrates high specificity, rapid response (90 min), and reliable performance in complex matrices. This work provides an integrated, stimuli-responsive strategy for simultaneous pathogen detection and eradication, offering promising potential for applications in food safety and clinical infection control.

In the present work, we describe a straightforward method for the synthesis of highly luminescent folic acid-functionalized copper nanoclusters (FA–CuNCs) using folic acid as a stabilizing agent and hydrazine hydrate as a reducing agent. In the presence of hydrogen peroxide (H₂O₂), the FA–CuNCs drive the oxidation of 3,3′,5,5′-tetramethyl benzidine (TMB) to its blue oxidized state (oxTMB), demonstrating good peroxidase-like activity. Adding tannic acid (TA) dramatically inhibits its catalytic activity making it possible to create a rapid, colorimetric sensing platform for TA. The proposed sensor exhibited notable sensitivity, achieving a low detection limit of 88.5 nM and a wide linear range from 2.00 × 10⁻⁷ to 4.00 × 10⁻⁶ mol dm⁻³, showing good selectivity against common interfering ions and biomolecules. This method was made considerably simpler and more portable by combining the colorimetric visibility with RGB color variation analysis based on a smartphone. Furthermore, the successful detection of TA in actual tea and coffee samples validated the method for practical applications. This portable, straightforward, cost effective and selective approach has a lot of potential for practical uses in environmental monitoring and food safety.

A polymetallic sulfide of Cu₂S/Ni₃S₂ is assembled in situ on nickel foam (NF), serving as a self-supported electrode and electrocatalyst for non-enzymatic glucose sensing. Benefiting from interfacial synergistic effects, the Cu₂S/Ni₃S₂/NF composite exhibits outstanding electrocatalytic capability toward glucose oxidation, with a high sensitivity of 22 750 µA mM⁻¹ cm⁻², a low limit of detection (LOD) of 0.51 µM, a broad linear detection range of 1 µM–1 mM, and good selectivity against interfering species. Density functional theory (DFT) calculations of the Cu₂S/Ni₃S₂ heterojunction are performed to reveal the density of states (DOS) and charge density difference. Effective interfacial electron transfer between Cu₂S and Ni₃S₂ modulates the electronic structure, thereby enhancing electrocatalytic activity. The optimal d-band centers (d_bc) of Cu and Ni in Cu₂S/Ni₃S₂ are beneficial for the promotion of glucose sensing sensitivity. This work provides an efficient strategy for fabricating polymetallic sulfides for application in next-generation non-enzymatic glucose sensing.

The reaction between decavanadate clusters and organic cations has attracted intensive research interest due to the interesting properties of the resulting materials. The asymmetric unit of their structure consists of a complete dihydrogen decavanadate anion ([H₂V₁₀O₂₈]⁻⁴), four organic 1-vinyl-1H-imidazol-3-ium cations (4[C₅H₇N₂]⁺¹), and four water molecules. The stability of the crystal arises from O–H⋯O, N–H⋯O and C–H⋯O bonding, with structural stabilization largely attributed to water molecules. Crystals have been grown by slow evaporation of the solution at room temperature. The compound has been chemically and spectroscopically characterized by a combination of elemental and thermal analyses, together with IR spectroscopy, and its structure was elucidated by X-ray diffraction. Density functional theory calculations combined with Hirshfeld surface, QTAIM, NCI, NBO, and frontier molecular orbital analyses reveal that the electronic structure of the hybrid system is governed by organic-to-inorganic charge transfer, with the organic moiety acting as an electron donor and the polyoxodecavanadate cluster serving as an electron acceptor. The combined experimental and theoretical results provide a coherent description of the bonding, noncovalent interactions, and electronic properties of the title compound.

The urgent demand for sustainable energy storage has driven the development of devices that combine high energy density with excellent power delivery. Supercapacitors, regarded as hybrid energy storage systems with characteristics of both batteries and capacitors, have emerged as attractive candidates for next-generation applications. The key challenge is to design electrode materials that exhibit high capacity, energy density, and durability. In this study, we report a metal–organic framework/polyaniline (MOF/PANI) nanocomposite electrode, engineered to overcome the poor conductivity of MOFs while leveraging their high surface area and porosity. The incorporation of conductive PANI enhances charge transport and structural integrity, enabling superior electrochemical performance. The MOF/PANI electrode achieves a specific capacity of 525.68 C g⁻¹ at 2 A g⁻¹, with 95.3% capacity retention after 4000 cycles. An asymmetric supercapacitor device fabricated from the nanocomposite delivers a specific capacity of 401.44 C g⁻¹ at 0.5 A g⁻¹ current density, along with an energy density of 72.48 Wh kg⁻¹ at a power density of 1299.99 W kg⁻¹. Notably, the device maintains 96% capacity retention over 50k cycles, reflecting outstanding durability. These results highlight the MOF/PANI nanocomposite as a high-performance electrode material, demonstrating significant potential for sustainable supercapacitor applications that bridge the gap between batteries and supercapacitors.

D-Galactose (D-Gal) is a monosaccharide crucial for various physiological processes in organisms. Abnormal variations in its levels are strongly correlated with several inherited metabolic conditions, including galactosemia. Thus, creating efficient, sensitive, and accurate detection methods for D-Gal is crucial for the early diagnosis of diseases. Herein, a novel multifunctional nanozyme derived from iron-doped carbon dots (Fe-CDs) was developed, integrating intrinsic fluorescence with robust peroxidase-like properties. Galactose oxidase catalyzes the oxidation of D-Gal to generate hydrogen peroxide (H₂O₂). The Fe-CD nanozyme facilitates the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by the resulting H₂O₂, ultimately producing blue oxidized TMB (oxTMB) with a distinct absorption peak at 652 nm. Simultaneously, oxTMB quenches the fluorescence of Fe-CDs at 526 nm through fluorescence resonance energy transfer, enabling dual-mode fluorescence-colorimetric detection. The limits of detection were determined to be 0.25 µM (fluorescence mode) and 19 µM (colorimetric mode), with corresponding linear ranges of 0.001–120 mM and 0.1–100 mM, respectively. Additionally, the sensing platform was successfully employed for the quantitative analysis of D-Gal in human serum samples. The fluorometric method achieved average recoveries of 95.6–102.6%, while the colorimetric method gave recoveries of 97.5–102.8%, exhibiting outstanding selectivity and reliability. This study provides a novel cascade system for D-Gal detection, highlighting its potential applications in the fields of biomedicine and biosensing.

Background: carbon dot nanozymes (CDszymes) hold significant promise for sensing applications due to their excellent water solubility and intrinsic fluorescence. However, conventional approaches for synthesizing CDszymes with high peroxidase-like (POD) activity remain largely empirical, relying on trial-and-error precursor screening, which limits rational design and optimization. Results: carbon dot nanoenzymes (CDszymes) demonstrate potential applications in nanoenzymatic sensing due to their excellent solubility and intrinsic fluorescence. However, conventional methods for synthesizing CDszymes with high peroxidase (POD) activity rely on empirical precursor screening. In this study, CDszymes with optimal POD activity were rationally designed by regulating the carbon chain length of dicarboxylic acids. Among the six synthesized CDszymes, ethanedioic acid-derived CDszymes-2 exhibited the highest POD activity, which catalyzes the oxidation of TMB by H₂O₂ to produce blue oxidized TMB (oxTMB), alongside fluorescence quenching via an inner filter effect. Utilizing glyphosate's (GLY) inhibition of acetylcholinesterase (AChE), a dual-mode colorimetric/fluorescent sensing platform was established, attaining detection limits of 13 ng mL⁻¹ (colorimetric) and 7 ng mL⁻¹ (fluorescent). Dual-mode sensing was successfully applied to detect GLY in fruit and vegetable samples, demonstrating potential for ultrasensitive trace-level pesticide detection in agricultural products.