Diffusion in a sol-gel-derived medium with a view toward biosensor applications.
Diffusion in a sol-gel-derived medium with a view toward biosensor applications.
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在溶胶-凝胶衍生介质中的扩散，着眼于生物传感器应用。
DOI：
10.1021/jp066021i
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
C. Tregidgo
中科院分区：
文献类型：
--
作者：
G. Hungerford;Ana Rei;M. Isabel C. Ferreira;K. Suhling;C. Tregidgo
用时间分辨荧光各向异性和光漂白后的荧光恢复研究了染料和荧光标记酶在溶胶-凝胶衍生介质中的扩散。这类介质具有稳定性好、加工温度低、孔隙率高、内比表面积大等特点，可作为生物活性分子的保护性固定化介质。这使得它成为生物传感器应用的合适候选者。玻璃的性质和良好的光学质量允许使用光谱学结合和访问光可寻址实体。这种类型的基质一旦形成，可以是从有序凝胶到坚固的玻璃块的任何东西，具体取决于老化过程。在这项工作中，我们应用共聚焦显微镜和时间分辨荧光技术来研究硅溶胶-凝胶衍生整体柱中旋转扩散和横向扩散随老化时间的变化。用Alexa Fluor 488标记一种酶，辣根过氧化物酶，并在基质老化过程中监测与酶和探针有关的旋转。从荧光素的初步FRAP测量中获得了约0.5×10~(-7)到4×10~(-7)cm~2 S(-1)之间的扩散系数，并与整体柱中加入的HRP的催化活性的差异有关。
Time-resolved fluorescence anisotropy and fluorescence recovery after photobleaching were applied to study the diffusion of dyes and a fluorescence-labeled enzyme in a sol-gel-derived medium. This type of medium exhibits attractive properties such as robustness, low processing temperature, high porosity, large internal surface area, and can act as protective immobilization media for biologically active molecules. This makes it a suitable candidate for biosensor applications. The glasslike nature and good optical quality allows for light addressable entities to be incorporated and accessed using spectroscopy. This type of matrix, once formed, can be anything from an ordered gel to a robust glassy block depending on the aging process. In this work we apply confocal microscopy and time-resolved fluorescence techniques to study both rotational and lateral diffusion with aging time within a silica sol-gel derived monolith. An enzyme, horseradish peroxidase, was labeled with Alexa Fluor 488 and rotation related to both the enzyme and the probe monitored during the matrix aging process. Diffusion coefficients of between ca. 0.5 x 10(-7) and 4 x 10(-7) cm2 s(-1) were obtained from preliminary FRAP measurements of fluorescein and correlated to differences in the catalytic activity of HRP incorporated in the monolith.