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The application of biomass‐based carbon materials in electrochemical sensing was limited due to their few active sites. So N and P double doped biomass pyrolytic carbon materials were designed in this paper. These gained materials were characterized by a series of characterization test techniques, and used as electrode modification to construct electrochemical sensors to detect baicalein (BA) and luteolin (LU). Under the best test condition, the minimum detectability of BA and LU was (7.8±0.25)×10−9 mol/L and (7.6±0.24)×10−9 mol/L (S/N=3), respectively. And the sensor performed well in the Shuanghuanglian oral liquid and the healthy human urine samples. [ABSTRACT FROM AUTHOR]

Summary: In order to well use waste biomass and realise the quantitative analysis of luteolin, the sorghum straw from the old broom was used to prepare biomass carbon material (CMS-PCSS) through the molten salt carbonization. Then the CMS-PCSS was characterised by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) Raman spectra (Raman), and N2 sorption analysis. In addition, the electrochemical performance of the CMS-PCSS based sensors was examined by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Under the first-rank experimental conditions, the electrochemical sensor established with this material performed well in the quantitative analysis and actual sample detection of luteolin, the detection range of luteolin was 0.05~10.0 pmol/L, and the actual achievable minimum detection limit was 0.019 pmol/L. [ABSTRACT FROM AUTHOR]

In this work, we describe an efficient and modular method for enantiodivergent accessing P(V)-stereogenic molecules by utilizing the catalytic atroposelective Catellani-type C-H arylation/desymmetric intramolecular N-arylation cascade reaction. The enantioselectivity of this protocol was proved to be tuned by the polarity of the solvent, thus providing a wide range of both chiral P(V)-stereogenic enantiomers in moderate to good yields with good to excellent enantiomeric excesses. Noteworthy is that the strategy developed herein represents an unprecedented example of solvent-dictated inversion of the enantioselectivity of P(V)-stereogenic compounds., (© 2024 Wiley‐VCH GmbH.)

Herein we report the colorimetry and an electrochemical for the determination of dopamine (DA) by using MnO 2 nanoparticles and graphene nanosheets composite (MnO 2 @G) that display oxidase mimicking property. MnO 2 @G could directly oxidize colorless 3,3',5,5'-tetramethylbenzidine (TMB) into a blue product (oxTMB) without extra oxidants such as H 2 O 2 . Nevertheless, the presence of DA will inhibit the TMB oxidation due to the presence of the competitive reaction of MnO 2 @G and DA, giving a product color change from blue to colorless. A colorimetric assay for detect the concentration of DA was worked out according to this finding. Response is linear in the 0.1 to 15 μM DA concentration range, and the detection limit is 0.14 μM. Wider detection range is achieved in an electrochemical method which is due to the pronounced electrocatalytic activity of MnO 2 @G. The MnO 2 @G was modified on the surface of the glassy carbon electrode in order to fabricate one type electrochemical sensor. The sensor achieves a wide detection two linear ranges from 0.4 to 70 μM, with the detection limit of 1.16 μM. The detection of DA in real serum sample proved that the nanozyme based on MnO 2 @G could be developed into a colorimetry and electrochemical dual-readout sensing platform., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Objective: To study the distribution of stress of simulating teeth with wedge shaped defects in the cervical region., Methods: The models of anisotropic enamel of the mandibular first premolar and the opposite maxillary first premolar crown were created. A defect was introduced into the model of mandibular premolar in the buccal cervical region along the enamelo-dentinal junction (DEJ). The stress distribution in the cervical region of the mandibular premolar was investigated considering lateral condition simulating working micromotions. In this case, the stroke was applied to the maxillary first mandibular in a stepping procedure using nonlinear contact analysis., Results: The stresses were concentrated in the defect of the enamel and dentin at the DEJ in the condition of lateral loading. As the defect length increased in size, the peak maximum principal stress (MPS) value and the magnitude of the stress field along the DEJ both increased., Conclusion: Undermined cervical DEJ had a significant effect on the stress distribution in the buccal cervical region.