Spectroscopic studies of solutes in aqueous solution
Spectroscopic studies of solutes in aqueous solution
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DOI：
10.1021/jp710105n
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发表时间：
2008-03-20
影响因子：
2.9
通讯作者：
Pollack, Gerald H.
中科院分区：
文献类型：
--
作者：
Chai, Bing-hua;Zheng, Jian-ming;Pollack, Gerald H.
利用紫外-可见光谱和荧光光谱研究了盐、糖和氨基酸水溶液的吸收和荧光特性。动机源于与各种亲水性表面相邻的“排除区”的非预期吸收光谱和荧光特征。这些特征暗示了与本体水不同的结构（Adv. Colloid Interface Sci. 2006，127，19）。在以下物质的溶液中观察到与在排除区中观察到的吸收峰相似的270 nm处的吸收峰：盐、Nafion 117溶液/膜、L-赖氨酸、D-丙氨酸、D-葡萄糖和蔗糖。为了确定吸收能量的命运，我们研究了这些溶液的荧光性质。在不同的激发波长下，该盐在480-490 nm处有荧光发射。LiCl的荧光强度高于NaCl，NaCl的荧光强度又高于KCl，这与吸收强度的顺序相同。在多个激发波长下，观察到了Nafion 117溶液/膜、L-赖氨酸、D-丙氨酸、D-葡萄糖和蔗糖的荧光。因此，至少一些吸收的能量作为荧光被释放。结果表明，在禁区内观察到的功能非常相似，这意味着周围的溶质水区类似于亲水性表面附近的水层。两者都可能比以前认为的更广泛地有序。
Absorption and fluorescence characteristics of aqueous solutions of salts, sugars, and amino acids were studied using UV-vis spectroscopy and spectrofluorometry. Motivation stemmed from unanticipated absorption spectral and fluorescence features of the "exclusion zone" seen adjacent to various hydrophilic surfaces. Those features implied a structure distinct from that of bulk water (Adv. Colloid Interface Sci. 2006, 127, 19). Absorption peaks at similar to 270 nm similar to those observed in the exclusion zone were seen in solutions of the following substances: salts, Nafion 117 solution/film, L-lysine, D-alanine, D-glucose and sucrose. To determine the fate of the absorbed energy, we studied the fluorescence properties of these solutions. The salts showed fluorescence emission around 480-490 nm under different excitation wavelengths. The fluorescence intensity of LiCl was higher than NaCl, which was in turn higher than KCl-the same ordering as the absorption intensities. Fluorescence of Nafion 117 solution/film, L-lysine, D-alanine, D-glucose and sucrose were observed as well, with multiple excitation wavelengths. Hence, at least some of the absorbed energy is released as fluorescence. The results show features closely similar to those observed in the exclusion zone, implying that the aqueous region around the solutes resembles the aqueous zone adjacent to hydrophilic surfaces. Both may be more extensively ordered than previously thought.