Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, C/Francisco Tomás y Valiente N°7, Campus de Excelencia de la Universidad Autónoma de Madrid, 28049 Madrid, Spain.
Analyst. 2011 Jan 21;136(2):340-7. doi: 10.1039/c0an00475h. Epub 2010 Nov 11.
The design and characterization of a new nanostructured organic-inorganic hybrid material and its application to L-lactic acid determination are described. This material is based on the integration of the enzyme lactate oxidase (LOx) and gold nanoparticles (AuNPs) into a sol-gel 3D polymeric network derived from (3-mercaptopropyl)-trimethoxysilane (MPTS) previously formed onto a gold surface. MPTS presents the advantage of forming a 3D polymeric network containing a large number of thiol tail groups distributed throughout its structure that enable both its anchoring onto gold surfaces and the AuNPs incorporation. Moreover, this matrix provides a biocompatible environment that preserves the catalytic activity of LOx after its immobilization and allows the incorporation of a high amount of enzyme, which is expected to improve the sensitivity of the final biosensing device. Characterization of the designed biosensing platform was performed using quartz crystal microbalance (QCM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. From the conjunction of these techniques, information about (i) the kinetic of LOx adsorption process in real time, (ii) the amount of LOx incorporated into the network, and (iii) the morphological characteristics at the nanometre level of the designed biosensing material was obtained. This information is very useful on the development of successful biosensing devices. Finally, the response of the biosensor to L-lactic acid was evaluated. The biosensor responds linearly to L-lactic acid in the range of 50 µM to 0.25 mM, with a sensitivity of 3.4 µA mM(-1) and a detection limit of 4.0 µM.
描述了一种新型的纳米结构有机-无机杂化材料的设计和表征及其在 L-乳酸测定中的应用。该材料基于将酶乳酸氧化酶（LOx）和金纳米粒子（AuNPs）整合到溶胶-凝胶 3D 聚合网络中，该网络由（3-巯丙基）-三甲氧基硅烷（MPTS）预先形成在金表面上。MPTS 的优点是形成含有大量硫醇尾基团的 3D 聚合网络，这些基团分布在其结构中，使其能够锚定在金表面上并掺入 AuNPs。此外，该基质提供了一个生物相容的环境，在固定化后保持 LOx 的催化活性，并允许掺入大量的酶，这有望提高最终生物传感设备的灵敏度。使用石英晶体微天平（QCM）、扫描电子显微镜（SEM）和原子力显微镜（AFM）技术对设计的生物传感平台进行了表征。通过这些技术的结合，可以获得有关（i）LOx 在实时吸附过程中的动力学，（ii）掺入网络中的 LOx 量，以及（iii）设计的生物传感材料的纳米级形貌特征的信息。这些信息对于开发成功的生物传感设备非常有用。最后，评估了生物传感器对 L-乳酸的响应。该生物传感器对 50 µM 至 0.25 mM 的 L-乳酸呈线性响应，灵敏度为 3.4 µA mM(-1)，检测限为 4.0 µM。
