Spermidine and spermine catalyze the formation of nanostructured titanium oxide
Spermidine and spermine catalyze the formation of nanostructured titanium oxide
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DOI：
10.1021/bm061221l
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发表时间：
2007-05-01
影响因子：
6.2
通讯作者：
Valentine, Ann M.
中科院分区：
文献类型：
--
作者：
Cole, Kathryn E.;Valentine, Ann M.
天然存在的多胺腐胺、尸胺、亚精胺和精胺是硅藻中发现的物种特异性长链多胺的类似物。扫描电子显微镜和能量色散光谱表明，可溶性钛（IV）前体与亚精胺和精胺，但不是腐胺或尸胺的反应，产生纳米结构的不规则多面体的氧化钛。在25 ℃下，亚精胺形成的颗粒的平均尺寸为400 +/-150 nm，精胺为140 +/-50 nm。虽然在室温下的颗粒是X-射线无定形的，退火研究表明，颗粒采用结晶度在较高的温度下的特性的TiO 2（TiO 2）。生物多胺的主要部分不与固体共沉淀，而是留在溶液中。动力学测量揭示了一个初始的快速步骤，然后是两个较慢的反应阶段。在25 ℃时，与亚精胺反应的k（1 obs）和k（2 obs）分别为5 × 10（-3）s（-1）和3.6 × 10（-4）s（-1），与精胺反应的k（1 obs）和k（2 obs）分别为4.8 × 10（-3）s（-1）和4.2 × 10（-4）s（-1）。总之，这些数据表明亚精胺和精胺是纳米结构的氧化钛沉淀的生物催化剂。
Naturally occurring polyamines putrescine, cadaverine, spermidine, and spermine are analogues of the species-specific long-chain polyamines found in diatoms. Scanning electron microscopy and energy-dispersive spectroscopy show that the reactions of a soluble Ti(IV) precursor with spermidine and spermine, but not putrescine or cadaverine, produce nanostructured irregular polyhedra of titanium oxide. At 25 degrees C, the average size of the particles formed with spermidine is 400 +/- 150 nm, and with spermine, 140 +/- 50 nm. Although the particles are X-ray amorphous at room temperature, annealing studies reveal that the particles adopt crystallinity at higher temperatures characteristic of anatase (TiO2). The major portion of the biopolyamines is not coprecipitated with the solid but is left in solution. Kinetic measurements reveal an initial fast step followed by two slower phases of reaction. At 25 degrees C, k(1obs) and k(2obs) for the reaction with spermidine are 5 x 10(-3) s(-1) and 3.6 x 10(-4) s(-1), respectively, and for spermine, 4.8 x 10(-3) s(-1) and 4.2 x 10(-4) s(-1), respectively. Taken together, the data suggest spermidine and spermine are biocatalysts for the precipitation of nanostructured titanium oxide.