Polyglycerol-bound phosphotriesterase enzyme model complexes for detection and hydrolysis of phosphorus species in aqueous solution

Phosphotriesterase models incorporating di(2-picolyl)amino ligands supported by m-xylylene or 2-hydroxy-m-xylylene scaffolds have been tethered to the periphery of a water-soluble hyperbranched polyglycerol (PG). In aqueous solution buffered at pH 7.4, the polymeric complexes of Zn²⁺ are useful receptors for polymeric indicator displacement assays for phosphate and pyrophosphate employing commercial complexometric indicators. Under the same conditions, the Co³⁺ effectively hydrolyze p-nitrophenylphosphate with approximately five orders of magnitude rate enhancement versus uncatalyzed hydrolysis. These systems offer promising results as mixed-metal dual detect-decontaminate materials for organophosphorus toxins under mild, neutral aqueous conditions.     

三价锰离子引发烯类单体在聚乙烯醇上接枝聚合的研究

<正> 无论是淀粉;纤维素,还是聚乙烯醇(PVA)的接枝反应,Ce(Ⅳ)被认为是一个十分有效的引发剂,已有较详尽的研究。与Ce(Ⅳ)相类似,Mn(Ⅲ)也可以和一些高聚物组成氧化还原引发体系,由此产生自由基,引发烯类单体在高分子主干上进行接枝聚合。Ranby等人,以焦磷酸络合的三价锰离子引发烯类单体在纤维素和淀粉的接枝反应中,获得了高效的接枝产物。有用这种引发体系在淀粉上接枝丙烯腈获得吸水276     

比色法测定微量焦磷酸根

本文描述了一种测量微量焦磷酸根的简洁、快速且低成本的方法 ,此法基于在 β-巯基乙醇存在下焦磷酸根与钼酸铵形成绿色化合物 ,在 5 80 nm进行吸收测定。     

基于碳点的荧光纳米开关灵敏检测Cu(Ⅱ)离子和焦磷酸盐

利用羟基与氨基在高温条件下反应,不断聚合生成碳点（CDs）,该碳点可发射不依赖激发波长的明亮的红色荧光.将CDs作为目标敏感荧光团时,发现Cu²⁺可特异性猝灭碳点的荧光,而焦磷酸盐（PPi）可在一定程度上恢复上述体系的荧光.其中,Cu²⁺对CDs的荧光猝灭是由于Cu²⁺与CDs发生络合反应,从而发生静态猝灭过程;而加入PPi之后,由于它与CDs的结合能力更强,因此Cu²⁺离开CDs的表面,体系的荧光得以恢复.在此基础上构建了一种高选择性、高灵敏度的off-on荧光纳米开关传感体系,分别用于Cu²⁺和PPi的定量检测,检出限分别达2.14 μmol/L和1.85 μmol/L.该传感体系可应用于实际样品检测,拓宽了荧光CDs的传感应用,为其在生物体内目标分子的检测提供了可能性.     

Synthesis and reactivity studies of α,α-difluoromethylphosphinates

The preparation and reactivity of some α,α-difluorophosphinates are investigated. Alkylation of H-phosphinates with LiHMDS and ClCF₂H gives the corresponding α,α-difluorophosphinates in good yield. Deprotonation of these reagents with alkyllithium or LDA is then studied. Subtle electronic effects translate into significant differences in the deprotonation/alkylation of the two ‘Ciba-Geigy reagents’ (EtO)₂CRP(O)(OEt)H (R=H, Me). On the other hand, attempted methylation of difluoromethyl-octyl-phosphinic acid butyl ester resulted in the exclusive alkylation of the octyl chain. Finally, reaction with carbonyl compounds results in the formation of 1,1-difluoro-2-phosphinoyl compounds.     

A new chemosensing ensemble for fluorescent recognition of pyrophosphate in water at physiological pH

A novel chemosensing ensemble that exhibits sensitive and selective recognitions of pyrophosphate in 100% aqueous solution at physiological pH has been developed. The chemosensing ensemble was constructed by a dinuclear Zn(II) complex of 2,6-bis[(bis(2-benzimidazolylmethyl)amino)methyl]-p-cresol and sodium fluorescein, the receptor–indicator pair is able to highly selectively discriminate pyrophosphate from phosphate and other anions in water at physiological pH.     

焦磷酸根嵌入后形成的交联水滑石的研究

合成了焦磷酸根交联水滑石，用XRD，FT－IR，DTA－TG，MASNMR等手段研究了焦磷酸根嵌入后形成的水滑后，提出了嵌入水滑石层间最多的离子为H2P2O7^2-，高温灼烧，P2O7^4-柱子交联到层上，且焦磷酸根离子链垂直位于水滑石层中，产物表面积为87m^2/g。     

New pyrophosphate analogues: a facile access to N-(O-alkyl-sulfamoyl)phosphoramidic acids via a simple and quantitative reaction of N-(O-alkylsulfamoyl)trimethylphospha-λ-azene with bromotrimethylsilane and water

A new strategy to prepare pyrophosphate analogues through selective and quantitative cleavage of N-(O-alkylsulfamoyl)trialkylphospha-λ⁵-azene esters (R-O-SO₂-NP(OR′)₃) has been developed. Using pure bromotrimethylsilane, N-(O-alkyl-sulfamoyl)tristrimethylsilylphospha-λ⁵-azenes (R-O-SO₂-NP(OSiMe₃)₃) have been easily obtained as intermediates. N-(O-Alkyl-sulfamoyl)phosphoramidic acids (R-O-SO₂-NH-P(O)(OH)₂) have been formed quantitatively by hydrolysis of the silylated intermediates.     

Analysis of polymerase chain reaction amplifications through phosphate detection using an enzyme-based microbiosensor in a microfluidic device

An electrochemical method was developed for analyzing PCR amplification through the detection of inorganic phosphates (Pi). This method coupled a microchip to a nanoparticle comprising poly-5,2'-5',2'-terthiophene-3'-carboxylic acid (poly-TTCA)/pyruvate oxidase (PyO) modified microbiosensor. It detects Pi produced from the pyrophosphate (PPi), which is released as a byproduct of PCR. After completion of PCR, PPi is hydrolyzed to Pi by inorganic pyrophosphatase. On the microbiosensor surface, pyruvate was converted to H2O2 by PyO in the presence of Pi and oxygen, and subsequently, the anodic current of enzymatically generated H2O2 was detected at +0.5 V versus Ag/AgCl. The CE-EC analysis was completed within 2 min in a coated channel with 75.0 mm separation length at the field strength of -200 V/cm. Excellent operation stability of poly-TTCA/PyO was observed for a long period of analysis. The reproducibility of the analysis yielded an RSD of 3.4% (n = 22) for the peak areas and 1.8% (n = 22) for the migration times. The sensitivity of the analysis was 0.59 +/- 0.01 nA/cycle with a regression coefficient of 0.971.     

Anthracene derivatives bearing two urea groups as fluorescent receptors for anions

For the recognition and sensing of anionic analytes, comparative studies were carried out on the anion bindings of pyrophosphate, H₂PO₄⁻, and dicarboxylates to the anthracene derivatives bearing two urea groups on the 1,8 and 9,10-positions as fluorescent chemosensors for anions. Their binding properties were compared using fluorescence and ¹H NMR, and the results were rationalized with an ab initio study.