Department of Physical and Environmental Sciences, University of Toronto Scarborough , Toronto, Ontario M1C 1A4, Canada.
ACS Appl Mater Interfaces. 2015 Feb 25;7(7):4081-8. doi: 10.1021/am507972b. Epub 2015 Feb 16.
In this proof-of-concept study, the fabrication of novel Au nanostructured indium tin oxide (Au-ITO) surfaces is described for the development of a dual-detection platform with electrochemical and localized surface plasmon resonance (LSPR)-based biosensing capabilities. Nanosphere lithography (NSL) was applied to fabricate Au-ITO surfaces. Oligomers of α-synuclein (αS) were covalently immobilized to determine the electrochemical and LSPR characteristics of the protein. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were performed using the redox probe Fe(CN)6 to detect the binding of Cu(II) ions and (-)-epigallocatechin-3-gallate (EGCG) to αS on the Au-ITO surface. Electrochemical and LSPR data were complemented by Thioflavin-T (ThT) fluorescence, surface plasmon resonance imaging (SPRi), and transmission electron microscopy (TEM) studies. EGCG was shown to induce the formation of amorphous aggregates that decreased the electrochemical signals. However, the binding of EGCG with αS increased the LSPR absorption band with a bathochromic shift of 10-15 nm. The binding of Cu(II) to αS enhanced the DPV peak current intensity. NSL fabricated Au-ITO surfaces provide a promising dual-detection platform to monitor the interaction of small molecules with proteins using electrochemistry and LSPR.
在这项概念验证研究中，描述了新型金纳米结构氧化铟锡（Au-ITO）表面的制造，用于开发具有电化学和基于局域表面等离子体共振（LSPR）的生物传感能力的双检测平台。采用纳米球光刻（NSL）制造 Au-ITO 表面。将α-突触核蛋白（αS）的低聚物共价固定以确定该蛋白的电化学和 LSPR 特性。使用氧化还原探针 Fe(CN)6进行循环伏安法（CV）和差分脉冲伏安法（DPV），以检测 Cu(II)离子和 (-)-表没食子儿茶素-3-没食子酸酯（EGCG）与 Au-ITO 表面上的 αS 的结合。电化学和 LSPR 数据由硫黄素-T（ThT）荧光、表面等离子体共振成像（SPRi）和透射电子显微镜（TEM）研究补充。结果表明，EGCG 诱导形成无定形聚集体，从而降低了电化学信号。然而，EGCG 与 αS 的结合增加了 LSPR 吸收带，出现了 10-15nm 的红移。Cu(II)与 αS 的结合增强了 DPV 峰电流强度。NSL 制造的 Au-ITO 表面为使用电化学和 LSPR 监测小分子与蛋白质相互作用提供了一种很有前途的双检测平台。
