Journal of The Chinese Chemical Society最新文献

Dopamine (DA) is a crucial neurotransmitter involved in metabolism, the immune system, and hormonal regulation. However, its accurate detection is challenging due to interference from compounds such as uric acid (UA) and ascorbic acid (AA). Here, we developed a polypyrrole/iron oxide/graphene nanoplatelet (PPy/Fe₃O₄/GNP)-modified glassy carbon electrode (GCE) for the selective detection of DA. FESEM analysis revealed a spherical bead-like morphology with a surface sheet of PPy, Fe₃O₄, and GNP. Electrochemical performance evaluation demonstrated that the PPy/Fe₃O₄/GNP-modified GCE possessed a high electroactive surface area (ECSA), that is, 0.099 cm², facilitating enhanced electron transfer. The sensor exhibited a linear detection range of 5.25–1000 μM and a limit of detection (LOD) of 5.25 μM for DA. Upon the addition of UA and AA, their oxidation peaks remained well-separated from the DA oxidation peak, confirming the selectivity of the PPy/Fe₃O₄/GNP-modified GCE. Furthermore, the sensor demonstrated excellent stability for 5 days with a Relative Standard Deviation (RSD) value of 28%, repeatability up to 50 cycles with an RSD value of 24.21%, and reproducibility on three different electrodes, giving the same response pattern with an RSD value of 5.55%. The real sample analysis using human serum yielded a recovery percentage of 82.17%–120.91%, indicating the sensor's reliability in biological sample detection. In conclusion, the PPy/Fe₃O₄/GNP-modified GCE is a highly sensitive and selective electrochemical sensor for DA detection, effectively minimizing interference from UA and AA. These findings highlight its potential for reliable neurotransmitter-sensing applications.

Metal sulfide-based materials have emerged as potential electrocatalysts for hydrogen evolution reactions (HER). In the past decades, significant developments have been achieved in enhancing their activity and durability for the HER. A facile and state-of-the-art approach to synthesize porous molybdenum disulfide (MoS₂) decorated with nickel (Ni) and platinum (Pt) nanoclusters is described for a synergistic effect on HER. The breakthrough of the research is to conduct a promising chemical vapor deposition (CVD) approach to generate the three-dimensional (3D) porous structure MoS₂ by complete reactions between the sublimation and the deposition. Additionally, the Pt nanoclusters and Ni are straightforwardly introduced by a hierarchical chemical reduction process to enhance the catalytic activity. Therefore, the porous MoS₂ and Pt-decorated porous Ni@MoS₂ (Pt@Ni@MoS₂) were employed as the electrochemical catalyst for HER. The results showed that the CVD process and the decorated Pt nanoclusters play important roles in determining the HER catalytic activity. The porous MoS₂ largely increased the surface area and active reaction sites for the HER performance. In addition, the decoration of Pt nanoclusters on porous Ni@MoS₂ can demonstrate the synergistic effect of Pt@Ni@MoS₂. Therefore, the overpotential and the Tafel slope of the Pt-decorated porous Ni@MoS₂ are determined as 43 mV and 56 mV/dec, respectively. The promising approach to synthesizing Pt-decorated porous Ni@MoS₂ for adjustment of different compositions is discussed in this study.

Naturally occurring xanthohumol O (2) and related compounds (3 and 4) were synthesized successfully. The core structure of chalcone was synthesized by Claisen−Schmidt condensation from appropriate acetophenones and benzaldehydes. The structures of synthetic compounds (2–4) were verified on the basis of NMR and HR-MS spectral data. The synthetic xanthohumol O showed strong anti-inflammatory effect with an EC₅₀.value of 0.79 μM.

In this work, the influence of solvent polarities on the excited-state intramolecular proton transfer (ESIPT) process of 2,2′-((1E,1′ E)-hydrazine-1,2-diylidenebis(methanylylidene))bis(4-(1,2,2-triphenylvinyl)phenol) (HDMTP) is systematically investigated in three solvents of distinct polarities (hexane, tetrahydrofuran, and acetonitrile) through DFT and TDDFT methodologies. We mainly elucidate the excited-state double proton transfer (ESDPT) mechanism in the HDMTP fluorophore. We analyze the geometric configuration, infrared (IR) vibrational spectra, and core-valence bifurcation (CVB) indexes to verify the enhancement of hydrogen bonds in the excited state. Meanwhile, we detect the HOMO and LUMO orbitals to investigate the influence of charge redistribution on the proton transfer process. The PESs are scanned to testify a stepwise ESDPT mechanism for HDMTP systems. We also propose that the decrease of solvent polarity can promote the occurrence of the ESDPT dynamic processes for the HDMTP system based on the calculated potential energy barriers for HDMTP in hexane, tetrahydrofuran, and acetonitrile solvents.

2-(2′-hydroxyphenyl)benzazoles (HBX) derivatives possess significant biological and photochemical applications. 3-benzooxazol-2-yl-3′-dimethylamino-biphenyl-2-ol (BYDBO) as one of novel HBX derivatives exhibits an asymmetrical configuration with intramolecular hydrogen bonding wire that present superior luminescent properties. Inspired by the regulated excited state dynamics by doping chalcogen elements, in this work, we mainly focus on clarifying the related excited state behaviors for three BYDBO derivatives (i.e., BYDBO-O, BYDBO-S and BYDBO-Se) theoretically. Elucidating the intramolecular hydrogen bonding interactions, photo-induced charge recombination, effects of atomic electronegativity related to oxygen elements, and relative excited state intramolecular proton transfer (ESIPT) behaviors, we mainly elaborate the chalcogen-element-related ESIPT mechanism for BYDBO derivatives. Based on our results, we sincerely wish our work could facilitate comprehending molecular excited state dynamics and designing novel luminescent organic materials for HBX derivatives.

This study investigated Pd-based electrocatalysts supported on corncob-derived biochar, pyrolyzed at various temperatures, for ethanol oxidation reaction in an alkaline medium, addressing challenges in direct ethanol fuel cells (DEFCs). Biochar, pyrolyzed at various temperatures (i.e., from 600 to 1000°C) displayed porous morphology and surface oxygenated groups, as confirmed by scanning electron microscopy and energy dispersive x-ray (SEM–EDX) and Fourier transform Infrared (FTIR) spectroscopy. The corncob biochar revealed a mesoporous structure based on Brunauer-Emmett-Teller (BET) analysis with graphitic carbon as confirmed by X-ray diffraction (XRD) analysis. The prepared Pd/biochar, with a trace amount of Ni, was investigated by SEM–EDX, transmission electron microscopy (TEM), XRD, and X-ray photoelectron spectroscopy (XPS). Among the synthesized catalyst composites, PdNi/CB600 demonstrated the least positive onset potential (−0.719 V), highest anodic peak current density (21.69 mA·cm⁻²), and highest I_f/I_b ratio (0.851) toward ethanol oxidation reaction in an alkaline medium, as determined by cyclic voltammetry (CV) and Tafel plot studies. Chronoamperometric analysis demonstrated the superior stability of PdNi/CB600 (65.33%) compared to commercial PdNi/C. These results highlight the corncob biochar's superior electrocatalytic activity over commercial carbon black as a support material for Pd-based electrocatalysts in a basic medium.

Focus of the figure: The COVID-19 pandemic emphasized the need for rapid, reliable healthcare diagnostics. We developed a handheld reader–QMIA–to enable quantitative lateral flow immunoassays and validated its performance through daily hormone monitoring. QMIA offers a practical solution for at-home, point-of-care, and field-based antigen testing, with enhanced sensitivity and usability. More details about this figure will be discussed by Dr. Huan-Cheng Chang and his co-workers on pages 693–701 in this issue.