Abstract:

A highly efficient surface plasmon resonance(SPR)-based DNA assay is developed,by employing noncovalently functionalized graphene nanosheets as the substrate,and enzymatic catalysis-induced polymerization as the mass relay.The objective of this strategy was manifold:first of all,to sensitize the overall SPR output by in situ optimized electrogeneration of graphene thin-film,that was characterized by atomic force micro-topography; secondly,to regulate the self-assembly and orientation of biotinylated capture probes on nickel-chelated nitrilotriacetic acid scaffolds,which were anchored onto graphene-supported pyrenyl derivatives; and lastly,to synergize the signal amplification via real-time conversion of the additive aniline into polyaniline precipitation by horseradish peroxidase-tagged reporters. With this setup,a precise and replicable DNA sensing platform for specific targets was achieved with a detection limit down to femtomolar,demonstrating a beneficial exploration and exploitation of two-dimensional nanomaterials as unique SPR infrastructure.The possibility of such “bottom-up” architecture mounted with “top-down” weight reactor would be most likely extensible and adaptable to protein determinations.

Key words: surface plasmon resonance, DNA, electrochemically reduced graphene nanosheets, microreactor, pyrene-tethered nitrilotriacetic acid, polymerization

摘要：

研究了一种高效的表面等离子共振（SPR）基DNA分析方法，利用非共价功能化的石墨烯纳米片作为基底，并以酶催化诱导的聚合作为质量中继。该策略有多方面的目标：首先，通过原位优化的石墨烯薄膜的电生成，该过程由原子力显微拓扑图表征，来敏化总体的SPR输出；其次，用于调制镍离子螯合的胺基三乙酸支架，其吸附在石墨烯支撑的苝基衍生物表面，上端生物素化捕获探针可以自组装，并保有一定的方向；最后，通过辣根过氧化物酶标记的报告单元，实时地将苯胺添加剂转化为聚苯胺沉淀，以协同实现信号的放大。运用上述配置，获得了一个对特异性DNA靶标精确且可重现传感的平台，检测下限达到飞摩尔水平，从而展现了以二维纳米材料为独特SPR基础设施的有益探索和开发。该“自下而上”的建构、与置顶“自上而下”的重量反应器，极有可能拓展并移植用于蛋白质的定量。

关键词: 表面等离子体共振, 脱氧核糖核酸, 电化学还原石墨烯纳米片, 微反应器, 苝接枝胺基三乙酸, 聚合