Advances in enzyme immobilization based on hierarchical porous metal-organic frameworks / 生物工程学报

As an excellent hosting matrices for enzyme immobilization, metal-organic framework (MOFs) provides superior physical and chemical protection for biocatalytic reactions. In recent years, the hierarchical porous metal-organic frameworks (HP-MOFs) have shown great potential in enzyme immobilization due to their flexible structural advantages. To date, a variety of HP-MOFs with intrinsic or defective porous have been developed for the immobilization of enzymes. The catalytic activity, stability and reusability of enzyme@HP-MOFs composites are significantly enhanced. This review systematically summarized the strategies for developing enzyme@HP-MOFs composites. In addition, the latest applications of enzyme@HP-MOFs composites in catalytic synthesis, biosensing and biomedicine were described. Moreover, the challenges and opportunities in this field were discussed and envisioned.

Solvent Sublation of L-Arginine and Its Separation Mechanism / 分析化学

The solvent sublation technique was applied for the separation and enrichment of L-Arg using dodecylbenzene sulfonic (DBSA) as the surfactant, di (2-ethylhexyl) phosphoric acid (P204) as the extractant and n-heptane as the organic solution. The solvent sublation was compared with the floatation complexation extraction, foam floatation and solvent extraction. The experimental results showed that enrichment ratio of 16.2 and removal rate of 97.2% to L-Arg were obtained by the solvent sublation under the conditions of room temperature, 0.09 g/L L-Arg aqueous solution 250 mL, DBSA concentration 0.15 g/L, the initial pH 7.0, volume of n-heptane 10 mL, volume of P204 4.5 mL, gas flow rate of 200 mL/min. The study of the kinetics indicated that the solvent sublation process could be divided into three stages distinctly. The processes of the first stage and the second stage followed the first order kinetics equation; the process of the third stage followed the zero order kinetics equation. The separation mechanism of solvent sublation was also discussed.