School of Science and Engineering, Waseda University , 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.
ACS Appl Mater Interfaces. 2012 Jul 25;4(7):3526-34. doi: 10.1021/am300595f. Epub 2012 Jun 25.
An aptasensor was designed on a nanocrystalline diamond (NCD) surface that combined with biological recognition elements, PDGF-binding aptamers, which inherently possess high affinity to PDGF-BB proteins. Functional components such as carboxylic acids (-COOH) and amines (-NH2) were directly introduced onto the NCD surface and used as probing units for immobilization of PDGF-binding aptamers. The surface coverage of different components on the NCD was analyzed by X-ray photoelectron spectroscopy (XPS) measurements, and the effects of various functionalizations on the NCD biosensor performance were investigated via fluorescence observations. The coverages of carboxyl and amine groups achieved were 12 and 23%, respectively, for the directly aminated and carboxylated NCD; however, the lower density of carboxyl groups on the functionalized surface did not deteriorate the performance of the COOH-NCD biosensor. Fluorescence investigations demonstrated comparable performance in sensitivity and selectivity for PDGF protein detection on COOH-NCD and NH2-NCD biosensors. Multiple regeneration tests clearly showed that the COOH-NCD biosensor as well as the NH2-NCD biosensor retained a high performance without exhibiting any noticeable degradation.
设计了一种基于纳米金刚石 (NCD) 表面的适体传感器，它结合了生物识别元件 PDGF 结合适体，PDGF 结合适体本身对 PDGF-BB 蛋白具有高亲和力。羧酸 (-COOH) 和胺 (-NH2) 等功能组件直接引入到 NCD 表面，并用作 PDGF 结合适体固定化的探测单元。通过 X 射线光电子能谱 (XPS) 测量分析了不同组件在 NCD 上的表面覆盖率，并通过荧光观察研究了各种功能化对 NCD 生物传感器性能的影响。直接氨化和羧化的 NCD 上的羧基和胺基组的覆盖率分别达到 12%和 23%；然而，功能化表面上较低密度的羧基基团并没有降低 COOH-NCD 生物传感器的性能。荧光研究表明，COOH-NCD 和 NH2-NCD 生物传感器在 PDGF 蛋白检测的灵敏度和选择性方面表现相当。多次再生测试清楚地表明，COOH-NCD 生物传感器和 NH2-NCD 生物传感器在没有表现出任何明显降解的情况下保持了高性能。
