Changchun Normal University

A highly sensitive surface-enhanced Raman spectroscopy (SERS) approach was established for the detection of monosultap using the nanosubstrate of β-CD/Trp/MgO/AgNPs which was MgO-protected silver nanoparticles (AgNPs) assembled tryptophan (Trp) and β-cyclodextrin (β-CD). Six nanosubstrates including AgNPs, MgO/AgNPs, Trp/AgNPs, β-CD/MgO/AgNPs, Trp/MgO/AgNPs and β-CD/Trp/MgO/AgNPs were compared for their enhancement effect on monosultap. Among them, β-CD/Trp/MgO/AgNPs had the greatest enhancement effect, with an enhancement factor (EF) reaching up to 1.95 × 10⁶. The nanosubstrate of β-CD/Trp/MgO/AgNPs was characterized by various instrumental techniques, such as transmission electron microscopy (TEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), zeta potential, X-ray diffraction (XRD), thermogravimetric analysis (TGA), ultraviolet-visible (UV-vis) and Fourier transform infrared (FT-IR). The binding of β-CD/Trp/MgO/AgNPs with monosultap was studied in detail. The optimum experimental conditions were confirmed through single-factor experiments and response surface analysis. The interferences from the coexisting substances (common metal ions, glucose and congeneric drugs) were investigated to evaluate the method selectivity. Under the optimal conditions, the standard curve equation of monosultap was established within the concentration range of 2.00 × 10^-8-1.00 × 10^-6 mol L^-1, with detection limit (LOD) of 0.970 nmol L^-1 (3σ/S). The SERS approach was utilized for detecting monosultap in several vegetables and fruits with the recoveries from 96.3 % to 105 %.

Soil salinization adversely threatens plant survival and food production globally. The mobilization of storage reserves in cotyledons and establishment of the hypocotyl/root axis (HRA) structure and function are crucial to the growth of dicotyledonous plants during the post-germination growth period. Here we report the adaptive mechanisms of wild and cultivated soybeans in response to alkali stress in soil during the post-germination growth period.

Differences in physiological parameters, microstructure, and the types, amounts and metabolic pathways of small-molecule metabolites and gene expression were compared and multi-omics integration analysis was performed between wild and cultivated soybean under sufficient and artificially simulated alkali stress during the post-germination growth period in this study.

Structural analysis showed that the cell wall thickness of wild soybean under alkali stress increased, whereas cultivated soybeans were severely damaged. A comprehensive analysis of small-molecule metabolites and gene expression revealed that protein breakdown in wild soybean cotyledons under alkali stress was enhanced, and transport of amino acids and sucrose increased. Additionally, lignin and cellulose syntheses in wild soybean HRA under alkali stress were enhanced.

Overall, protein decomposition and transport of amino acids and sucrose increased in wild soybean cotyledons under alkali stress, which in turn promoted HRA growth. Similarly, alkali stress enhanced lignin and cellulose synthesis in the wild soybean HRA, which subsequently enhanced cell wall synthesis, thereby maintaining the stability and functionality of the HRA under alkali stress. This study presents important practical implications for the utilization of wild plant resources and sustainable development of agriculture.

Coordination of metal ions with biointerfaces plays essential roles in numerous physiological and pathological processes, such as signal transduction, enzymatic catalysis, and membrane organization. Growing insights underscore the ubiquitous and significant role of water structure in modulating interactions at biointerfaces. The intrinsic surface heterogeneity of biointerfaces significantly modulates water structure and affects interfacial interactions. Especially, the surfaces of proteins and membranes are complex and heterogeneous, both chemically and geometrically, with nanoscale mixed hydrophilic/hydrophobic groups and dislocated positions. However, little is known about the effect of dislocated heterogeneity on metal ion coordination at biointerfaces. Herein, we developed a simplified ion coordination biointerface model with dislocated chemical and geometrical heterogeneity and explored the effect of atomic-scale dislocated proximal groups on interfacial properties and the resultant influence on ion coordination. Results showed that the surface charging state, hydrogen bonding environment, and interfacial water structure were modulated by the atomic-scale dislocated hydrophobic and hydrophilic mixing, thereby affecting ion coordination. Importantly, we found that structured water (water molecules at or near the biointerface with ordered hydrogen-bonded networks) plays a dominant role in interfacial ion coordination, where enhanced hydrogen-bonded structured water significantly hindered ion coordination. These findings underscore the important role of atomic dislocation and structured water in modulating the interactions between biological heterogeneous surfaces and ions, providing valuable guidance for the design and application of ion coordination-involved surfaces in both biological and industrial fields.