Zhang P, Tan W
Department of Chemistry and Center for Chemical Research at the Interface of Bio/Nano, University of Florida, Gainesville 32601, USA.
Fresenius J Anal Chem. 2001 Feb;369(3-4):302-7. doi: 10.1007/s002160000624.
The development of biosensors has been one of the key areas in biotechnology and biomedical studies. Often it is difficult to investigate the immobilized biomolecules on the surfaces for biosensor optimization. Atomic force microscopy (AFM) should provide an ideal means for the visualization of biosensor surface and for the investigation of biomolecule activities. Therefore, AFM has been employed to study the surface topography of immobilized glutamate dehydrogenase (GDH) on two-dimensional glutamate biosensor surfaces. Correlation between the surface topography and the activity of the biosensor was investigated. Surface analysis has revealed that the enzymatic activity of the immobilized GDH molecules on the biosensor surface is linked to surface roughness, as measured by the peak-to-valley distance. Fractal dimension of the immobilization sensor surface was found to be a good parameter for judging the quality of the immobilized biosensors. As enzyme immobilization time increases, the biosensor has its maximum activity with around 18 h of immobilization in 10(-6) M GDH solution. Various biosensors prepared under different experimental conditions have been studied by AFM. This technique is shown to be an effective tool to characterize biosensor surfaces.
生物传感器的发展一直是生物技术和生物医学研究的关键领域之一。对于生物传感器优化而言，研究固定在表面的生物分子往往具有难度。原子力显微镜（AFM）应为可视化生物传感器表面以及研究生物分子活性提供理想手段。因此，AFM已被用于研究二维谷氨酸生物传感器表面上固定化的谷氨酸脱氢酶（GDH）的表面形貌。研究了表面形貌与生物传感器活性之间的相关性。表面分析表明，生物传感器表面上固定化的GDH分子的酶活性与通过峰谷距离测量的表面粗糙度相关。发现固定化传感器表面的分形维数是判断固定化生物传感器质量的良好参数。随着酶固定化时间的增加，生物传感器在10^(-6) M GDH溶液中固定约18小时时具有最大活性。通过AFM研究了在不同实验条件下制备的各种生物传感器。该技术被证明是表征生物传感器表面的有效工具。
