Herein, a stable and ultra-sensitive rutin electrochemical sensor was successfully developed. This sensor based on glassy carbon electrode (GCE) modified with C-GCS@ZIF-F/PL nanocomposite, which was made of thermally carbonized glucose (GCS) doped with flower-like ZIF (ZIF-F) and pencil lead (PL). The electrochemical response of rutin was considerably significant at C-GCS@ZIF-F/PL/GCE, demonstrating favorable conductivity and electrocatalytic properties for detection of rutin. Under optimal conditions, the linear range is 0.1–100 μM, with a low detection limit (LOD) of 0.0054 μM. It also exhibits excellent stability, reproducibility, as well as selectivity over common interfering ions such as Na + , uric acid, quercetin and riboflavin, etc. Meanwhile, the practical utility of developed sensor was evaluated in food samples including honey, orange, and buckwheat tea, achieving satisfactory recovery rates ranging from 98.2% to 101.7%. This paper introduces a novel technique for the detection of rutin in foods.
Guoqing Wang,Jianfei Wang,Xinping Wang,Yuanyuan Meng,Xiangzhen Feng,Gaoli Liu,Dong-An Wang,Changjiang Fan
Uncontrolled traumatic hemorrhage is a leading cause of preventable death. As two main forms of hemostatic materials, however, both sponges and hydrogel adhesives usually fail to control massive hemorrhage due to their respective shortcomings. Hemostatic sponge shows weak tissue adhesion, while the gelation process of hydrogel makes it difficult to seal high-pressure bleeding wounds. There is an urgent need to develop next-generation hemostats combining the advantages of sponges and hydrogel adhesives. Herein, a general methodology to prepare novel Fe 3+ -laden porous material (Fe 3+ @GCS) for rapid hemostasis of the high-pressure and severe hemorrhages is proposed, which is fabricated by loading ferric chloride with ethanol into the catechol-modified carboxylated gelatin sponge (GCS). Notably, porous Fe 3+ @GCS can undergo water-triggered rapid transformation to robust-adhesive hydrogels. The sealing strength of Fe 3+ @GCS on wet tissues reaches an astonishing ≈600 mm Hg. Rapid water uptake of Fe 3+ @GCS around wound not only concentrates blood components but also excludes interfacial water, facilitating blood clotting and wound sealing with the in situ formed sticky hydrogel. Fe 3+ @GCS can efficiently stop the high-pressure hemorrhaging from traumatic injuries of arteries and hearts in rats and pigs, respectively, via a simple and short-time pressing. Furthermore, the wound sealing by Fe 3+ @GCS promotes wound repair and healing.
Glycine cleavage system (GCS) plays a central role in one-carbon (C1) metabolism and receives increasing interest as a core part of the recently proposed reductive glycine pathway (rGlyP) for assimilation of CO 2 and formate. Despite decades of research, GCS has not yet been well understood and kinetic data are barely available. This is to a large degree because of the complexity of GCS, which is composed of four proteins (H, T, P, and L) and catalyzes reactions involving different substrates and cofactors. In vitro kinetics of reconstructed microbial multi-enzyme glycine cleavage/synthase system is desired to better implement rGlyP in microorganisms like Escherichia coli for the use of C1 resources. Here, we examined in vitro several factors that may affect the rate of glycine synthesis via the reverse GCS reaction. We found that the ratio of GCS component proteins has a direct influence on the rate of glycine synthesis, namely higher ratios of P protein and especially H protein to T and L proteins are favorable, and the carboxylation reaction catalyzed by P protein is a key step determining the glycine synthesis rate, whereas increasing the ratio of L protein to other GCS proteins does not have significant effect and the ratio of T protein to other GCS proteins should be kept low. The effect of substrate concentrations on glycine synthesis is quite complex, showing interdependence with the ratios of GCS component proteins. Furthermore, adding the reducing agent dithiothreitol to the reaction mixture not only results in great tolerance to high concentration of formaldehyde, but also increases the rate of glycine synthesis, probably due to its functions in activating P protein and taking up the role of L protein in the non-enzymatic reduction of H ox to H red . Moreover, the presence of some monovalent and divalent metal ions can have either positive or negative effect on the rate of glycine synthesis, depending on their type and their concentration.
危险品化学品经营许可证（带存储）