Department of Applied Physical Chemistry, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
Biosens Bioelectron. 2010 May 15;25(9):2038-44. doi: 10.1016/j.bios.2010.01.032. Epub 2010 Feb 2.
The design and characterization of a lactate biosensor using a nanostructured rough gold surface as a transducer is reported. The biosensor is developed by immobilization of lactate oxidase (LOx), on a rough gold electrode modified with a self-assembled monolayer of dithiobis-N-succinimidyl propionate (DTSP). This bifunctional reagent preserves the rough gold structure and allows further covalent immobilization of the enzyme through the terminal succinimidyl groups. The rough gold electrode is characterized using field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). The preferential orientation and average crystallite size are obtained by X-ray diffraction (XRD). The resulting lactate oxidase monolayers are characterized by electrochemical impedance spectroscopy (EIS). This nanostructured transducer allows higher mediated electrocatalytic activity than polycrystalline ones. The biosensor response to increasing lactate concentrations, using hydroxymethylferrocene as a redox mediator in solution, is linear up to 1.2 mM with a sensitivity of 1.49 microA mM(-1).
本文报道了一种基于纳米结构粗糙金表面作为换能器的乳酸生物传感器的设计与特性。该生物传感器是通过将乳酸氧化酶（LOx）固定在带有二硫代双（N-琥珀酰亚胺基丙酸酯）（DTSP）自组装单层的粗糙金电极上来制备的。这种双功能试剂保留了粗糙金的结构，并允许通过末端琥珀酰亚胺基进一步共价固定酶。使用场发射扫描电子显微镜（FE-SEM）和原子力显微镜（AFM）对粗糙金电极进行了表征。通过 X 射线衍射（XRD）获得了择优取向和平均晶粒尺寸。通过电化学阻抗谱（EIS）对所得乳酸氧化酶单层进行了表征。这种纳米结构的换能器具有比多晶型更高的介体型电催化活性。该生物传感器在溶液中使用羟甲基二茂铁作为氧化还原介体，对乳酸浓度的增加具有线性响应，线性范围可达 1.2 mM，灵敏度为 1.49 μA mM(-1)。
