流动注射电化学发光分析法测定维生素B1及在尿液分析中的应用

将在线恒电流电解产生ClO-与Luminol构成了较强的化学发光体系,基于维生素B1对该化学发光体系有抑制作用,结合流动注射技术,建立了测定维生素B1的流动注射电化学发光新方法,并把它应用于尿液分析中. 该方法在维生素B1的浓度为1.0×10-10～1.0×10-8 mmol/mL之间分段回归,呈良好的线性,检出限达到5.0×10-11 mmol/mL.     

Emulsions stabilised by casein and hyaluronic acid: Effects of high intensity ultrasound on the stability and vitamin E digestive characteristics

This study aimed to prepare an emulsion stabilised by an ultrasound-treated casein (CAS)-hyaluronic acid (HA) complex and to protect vitamin E during in vitro digestion. It was found that high-intensity ultrasound (HIU) treatment significantly changed the hydrogen bonding, electrostatic interaction and hydrophobic interaction between CAS and HA, reduced the particle size of the CAS-HA complex, increased the intermolecular electrostatic repulsion, and thus significantly improved the emulsifying properties of the CAS-HA complex. Meanwhile, the creaming index (CI) and confocal laser scanning microscopy images showed that the stability of the CAS-HA-stabilised emulsion was the best when treated at 150 W for 10 min, which could be attributed to the enhanced adsorption capacity of the CAS-HA complex at the oil–water interface and the viscosity of the formed emulsion. In vitro digestion experiments revealed that the emulsion stabilised by the ultrasound-treated CAS-HA complex had a good protective effect on vitamin E. This study is significant for the development of emulsions for the delivery of lipophilic nutrients.     

Multistimuli-responsive pyrene-based lanthanide (III)-MOF construction and applied as dual-function fluorescent chemosensors for trace water and vitamins molecules

Three novel isostructural 3D porous metal–organic frameworks (3D MOFs) Ln-TBAPy (Ln = Sm (1), La (2), and Nd (3); H₄TBAPy = 1,3,6,8-tetrakis (p-benzoic acid)pyrene) were synthesized, encompassing a π-conjugated organic ligand with a pyrene functionality. In particular, the crystal structure of [Sm₃ (TBAPy)₂ ((μ₂-H₂O)₂(OH)₂]?(guests) (complex 1) was determined by X-ray single-crystal diffraction and displayed excellent performance in luminescent, which featured the alb topology and remarkable multiple pores dimensions. The complex 1 was utilized to determine the pH-dependent and temperature-dependent fluorescence under multistimuli responses, which exhibits its unusual photophysical characteristics and outstanding stability under special conditions. Markedly, the complex 1 probe achieves ultra-sensitive turn-on detection of trace water in organic solvent dioxane, exhibiting an ultra-low detection limit of 0.005% (v/v). In addition, we have explored that it has excellent fluorescence detection selective effect on various biological small molecule vitamins. On the one hand, the complex 1 can sense Vit-B₆ with unique fluorescent switch ‘turn-on-off’ behavior, based on the changing concentration of Vit-B₆ in MOF channel and hydrogen bond between host–guest interaction. On the other hand, complex 1 has high sensitivity to the quenching of Vit-B₉ and Vit-K₃, with the LOD as low as 0.32 μM, and 3.94 μM, respectively. Our synthesis strategy of Ln-TBAPy MOF materials will play simultaneously multiple roles and open up an effective avenue to dual-function fluorescence sensor of water and biological small molecule vitamins.