Xiao Yi, Pavlov Valeri, Shlyahovsky Bella, Willner Itamar
Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Chemistry. 2005 Apr 22;11(9):2698-704. doi: 10.1002/chem.200400988.
The complex Os(II)-bisbipyridine-4-picolinic acid, Os(bpy)(2)PyCO(2)H (1), mediates the biocatalyzed growth of Au nanoparticles, Au NPs, and enables the spectroscopic assay of biocatalyzed transformations and enzyme inhibition by following the Au NP plasmon absorbance. In one system, Os(bpy)(2)PyCO(2)H mediates the biocatalyzed oxidation of glucose and the growth of Au NPs in the presence of glucose oxidase, GOx, AuCl(4) (-), citrate and Au NP seeds. The mechanism of the Au NPs growth involves the oxidation of the Os(bpy)(2)PyCO(2)H complex by AuCl(4) (-) to form Os(bpy)(2)PyCO(2)H and Au(I). The Os(bpy)(2)PyCO(2)H complex mediates the GOx biocatalyzed oxidation of glucose and the regeneration of the mediator 1. Citrate reduces Au(I) and enlarges the Au seeds by the catalytic deposition of gold on the Au NP seeds. In the second system, the enzyme acetylcholine esterase, AChE, is assayed by the catalytic growth of the Au NPs. The hydrolysis of acetylcholine (2) by AChE to choline is followed by the Os(bpy)(2)PyCO(2)H mediated oxidation of choline to betaine and the concomitant growth of the Au NPs. The mediated growth of the Au NPs is inhibited by 1,5-bis(4-allyldimethylammonium-phenyl)pentane-3-one dibromide (3). A competitive inhibition process was demonstrated (K(M)=0.13 mM, K(I)=2.6 microM) by following the growth of the Au NPs.
配合物二（联吡啶）-4-吡啶甲酸锇（II），即Os(bpy)(2)PyCO(2)H（1），介导了金纳米颗粒（Au NPs）的生物催化生长，并通过跟踪Au NP等离子体吸光度实现了对生物催化转化和酶抑制的光谱分析。在一个体系中，Os(bpy)(2)PyCO(2)H在葡萄糖氧化酶（GOx）、AuCl(4) (-)、柠檬酸盐和Au NP种子存在的情况下，介导葡萄糖的生物催化氧化以及Au NPs的生长。Au NPs生长的机制涉及Os(bpy)(2)PyCO(2)H配合物被AuCl(4) (-)氧化形成Os(bpy)(2)PyCO(2)H和Au(I)。Os(bpy)(2)PyCO(2)H配合物介导GOx对葡萄糖的生物催化氧化以及介体1的再生。柠檬酸盐还原Au(I)并通过在Au NP种子上催化沉积金来扩大Au种子。在第二个体系中，通过Au NPs的催化生长来测定乙酰胆碱酯酶（AChE）。AChE将乙酰胆碱（2）水解为胆碱后，Os(bpy)(2)PyCO(2)H介导胆碱氧化为甜菜碱并伴随Au NPs的生长。1,5-双（4-烯丙基二甲基铵苯基）戊烷-3-酮二溴化物（3）抑制了Au NPs的介导生长。通过跟踪Au NPs的生长证明了一个竞争性抑制过程（K(M)=0.13 mM，K(I)=2.6 microM）。
