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Co n -1 TMO n -2 + ( n = 6-8), (TM = V, Cr, Mn, and Fe) clusters are investigated using density functional theory calculations. The transition metal atoms preferentially replace one Co atom at sites where the number of metal-oxygen bonds is maximized, forming more stable structures. The evaporation of a Co atom is the most fragile dissociation channel for both pure and doped species. Bare cobalt oxide clusters exhibit parallel spin ordering, whereas both parallel and antiparallel spin ordering are observed in the doped species. Notably, a ferromagnetic-to-ferrimagnetic transition occurs in the V-doped clusters, while the ferromagnetic behavior is enhanced in the Fe-doped species., Competing Interests: The authors declare no competing financial interest., (This journal is © The Royal Society of Chemistry.)

Twelve compounds were isolated from Mussaenda saigonensis aerial parts through phytochemical analysis and the genus Mussaenda is the first place where the compounds 4-6 and 11-12 have been found. Based on the ability to inhibit NO production in RAW264.7 cells, compound 2 has demonstrated the strongest anti-inflammatory activity in vitro with an IC 50 of 7.6 μM, as opposed to L-NMMA's IC 50 of 41.3 μM. Compound 12 was found to be the most effective inhibitor of alpha-glucosidase enzyme in vitro , with an IC 50 value of 42.4 μM (compared to 168 μM for acarbose). Compounds 1-12 were evaluated in vitro for antimicrobial activity using the paper dish method. Compound 11 demonstrated strong antifungal activity against M. gypseum with a MIC value of 50 μM. In silico docking for antimicrobial activity, pose 90 or compound 11 docked well to the 2VF5 enzyme, PDB, which explains why compound 11 had the highest activity in vitro . Entry 2/pose 280 demonstrated excellent anti-inflammatory activity in silico . The stability of the complex between pose 280 and the 4WCU enzyme for anti-inflammatory activity has been assessed using molecular dynamics over a simulation course ranging from 0 to 100 ns. It has been found to be stable from 60 and 100 ns. The Tyr 159 (95%, H-bond via water bridge), Asp 318 (200%, multiple contacts), Met 273 (75%, hydrophobic interaction via water bridge), and Gln 369 (75%, H-bond via water bridge) interacted well within the time range of 0 to 100 ns. It has more hydrophilic or polar pharmacokinetics., Competing Interests: No potential conflict of interest was reported by the authors., (This journal is © The Royal Society of Chemistry.)

Silver nanoparticles (AgNPs) have been regarded as a highly promising substrate for surface-enhanced Raman scattering (SERS) sensors. In this study, we focused on the electrochemical synthesis method by developing three kinds of AgNPs using three different electrolytes: citrate (e-Ag-C), oleic acid (e-Ag-O) and fish mint ( Houttuynia cordata Thunb.) extract (e-Ag-bio). The as-prepared AgNPs were characterized and then employed as SERS substrates to detect the pesticide thiram. The obtained results show that e-Ag-O exhibits the best SERS performance. The effect of the coating agent was explained by chemical and electromagnetic enhancements (CM and EM). Although thiram could absorb onto e-Ag-C at the highest level, allowing its Raman signal to be best enhanced via the CM, the smallest interparticle distance of e-Ag-O could have resulted in the largest improvement in the EM. Using e-Ag-O to develop SERS-based sensors for thiram, we obtain the impressive detection limit of 1.04 × 10 -10 M in standard samples and 10 -9 M in tea leaves. The linear ranges are from 10 -4 M to 10 -7 M and from 10 -7 M to 10 -9 M, covering the maximum residue levels for plant commodities established by the United States Environment Protection Agency and European Food Safety Authority (2-13 ppm ∼7.7 × 10 -6 M to 5 × 10 -5 M)., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)

In this study, we fabricated a composite of NiO-ZnO/PANI-CNTs on a fluorine tin oxide (FTO) electrode and examined the electrochemical sensing behavior of the modified electrode to detect methanol in aqueous solution. The structural, morphological, and electrochemical properties of the composite were characterized using various methods such as X-ray diffraction (XRD), EDS, FTIR, X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and electrochemical techniques such as cyclic voltammetry (CV) and chronoamperometry (CA). The composite-based electrode showed excellent electrocatalytic activity and selectivity for methanol oxidation. The calibration equation obtained was Δ I = 0.0003 × C MeOH + 0.02811, with a high correlation coefficient of 0.9993, over a wide detection range of 0 to 500 mM. The material exhibits great potential for the fabrication of sensors to detect methanol in commercial products. Real gasoline samples have been selected to evaluate the practical performance and feasibility of this as-prepared sensor. The experimental data indicated that the recovery of gasoline samples is about 98%, indicating this to be an appropriate detection procedure for effective electrochemical determination of MeOH in real gasoline samples., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

This study delves into the advanced integration of a ternary heterogeneous Z-scheme photocatalyst, TiO 2 /CuInS 2 /OCN (OCN: O-g-C 3 N 4 ), with carbon quantum dot (CQD) to improve the degradation efficiency of reactive yellow 145 (RY145) dye in water. Through a systematic examination, we elucidated the photocatalytic mechanisms and the role of radicals, electrons, and holes in the treatment process. Our findings revealed that this novel catalyst integration significantly boosted RY145 degradation efficiency, achieving 98.2%, which is markedly higher than the efficiencies which could be achieved using TiO 2 /CuInS 2 /OCN alone. Moreover, the TiO 2 /CuInS 2 /OCN/CQD photocatalyst demonstrated superior rate performance over its components. Comprehensive evaluations, including photoelectrochemical and radical tests, further confirmed the efficiency of the integrated system, adhering to Z-scheme principles. The catalyst showcased remarkable stability, with over 94% reusability after five reaction cycles. These findings pave the way for the potential use of the TiO 2 /CuInS 2 /OCN/CQD photocatalyst as an innovative solution for water pollutant treatment via photocatalytic technology., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

In this study, crystalline spinel zinc ferrite nanoparticles (ZnFe 2 O 4 NPs) were successfully prepared and proposed as a high-performance electrode material for the construction of an electrochemical sensing platform for the detection of paracetamol (PCM). By modifying a screen-printed carbon electrode (SPE) with ZnFe 2 O 4 NPs, the electrochemical characteristics of the ZnFe 2 O 4 /SPE and the electrochemical oxidation of PCM were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), chronoamperometry (CA), and differential pulse voltammetry (DPV) methods. The calculated electrochemical kinetic parameters from these techniques including electrochemically active surface area (ECSA), peak-to-peak separation (Δ E p ), charge transfer resistance ( R ct ), standard heterogeneous electron-transfer rate constants ( k 0 ), electron transfer coefficient ( α ), catalytic rate constant ( k cat ), adsorption capacity ( Γ ), and diffusion coefficient ( D ) proved that the as-synthesized ZnFe 2 O 4 NPs have rapid electron/mass transfer characteristics, intrinsic electrocatalytic activity, and facilitate the adsorption-diffusion of PCM molecules towards the modified electrode surface. As expected, the ZnFe 2 O 4 /SPE offered excellent analytical performance towards sensing of PCM with a detection limit of 0.29 μM, a wide linear range of 0.5-400 μM, and high electrochemical sensitivity of 1.1 μA μM -1 cm -2 . Moreover, the proposed ZnFe 2 O 4 -based electrochemical nanosensor also exhibited good repeatability, high anti-interference ability, and practical feasibility toward PCM sensing in a pharmaceutical tablet. Based on these observations, the designed electrochemical platform not only provides a high-performance nanosensor for the rapid and highly efficient detection of PCM but also opens a new avenue for routine quality control analysis of pharmaceutical formulations., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)

The rational design of nanomaterials for electrochemical nanosensors from the perspective of structure-property-performance relationships is a key factor in improving the analytical performance toward residual antibiotics in food. We have investigated the effects of the crystalline phase and copper loading amount on the detection performance of Cu-MoS 2 nanocomposite-based electrochemical sensors for the antibiotic chloramphenicol (CAP). The phase composition and copper loading amount on the MoS 2 nanosheets can be controlled using a facile electrochemical method. Cu and Cu 2 O nanoparticle-based electrochemical sensors showed a higher CAP electrochemical sensing performance as compared to CuO nanoparticles due to their higher electrocatalytic activity and conductivity. Moreover, the design of Cu-MoS 2 nanocomposites with appropriate copper loading amounts could significantly improve their electrochemical responses for CAP. Under optimized conditions, Cu-MoS 2 nanocomposite-based electrochemical nanosensor showed a remarkable sensing performance for CAP with an electrochemical sensitivity of 1.74 μA μM -1 cm -2 and a detection limit of 0.19 μM in the detection range from 0.5-50 μM. These findings provide deeper insight into the effects of nanoelectrode designs on the analytical performance of electrochemical nanosensors., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)

4-Nitrophenol (4-NP) is a promulgated priority pollutant, which can cause a negative impact on human health. The development of a direct and effective technique for the rapid detection and screening of 4-NP is, therefore, of urgent need. In this study, the blue luminescent sulfur-doped graphene quantum dots (S-GQDs) with a size of 1-5 nm are fabricated using a one-step pyrolysis procedure in the presence of citric acid and 3-mercaptosuccinic acid. The S-GQDs exhibit a strong emission band at 450 nm under the excitation of 330 nm UV light. 4-NP can serve as the fluorescence quencher by the π-π interaction with S-GQD, resulting in the linear decrease in fluorescence intensity after the addition of various 4-NP concentrations ranging from 10 nM to 200 μM. The S-GQDs serve as the sensing probe to enhance the analytical performance on 4-NP detection with the limit of detection values of 0.7 and 3.5 nM in deionized water and wastewater, respectively. The S-GQD based sensing platform can be used to detect 4-NP in different matrices of water and wastewater. In addition, the detected percentages of spiked 4-NP concentrations in the presence of different matrices and interferences are in the range of (98 ± 5)-(108 ± 2)%. Moreover, the S-GQD based paper sensor can rapidly screen 4-NP in wastewater within 1 min. Results obtained in this study clearly demonstrate the superiority of S-GQDs as a promising fluorescence probe for highly sensitive and selective detection of a wide concentration range of 4-NP in deionized water and wastewater., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)