AbstractThe authors describe an electrochemical method for the determination of the single-stranded DNA (ssDNA) oligonucleotide with a sequence derived from the genom of hepatitis B virus (HBV). It is making use of circular strand displacement (CSD) and rolling circle amplification (RCA) strategies mediated by a molecular beacon (MB). This ssDNA hybridizes with the loop portion of the MB immobilized on the surface of a gold electrode, while primer DNA also hybridizes with the rest of partial DNA sequences of MB. This triggers the MB-mediated CSD. The RCA is then initiated to produce a long DNA strand with multiple tandem-repeat sequences, and this results in a significant increase of the differential pulse voltammetric response of the electrochemical probe Methylene Blue at a rather low working potential of −0.24 V (vs. Ag/AgCl). Under optimal experimental conditions, the assay displays an ultrahigh sensitivity (with a 2.6 aM detection limit) and excellent selectivity. Response is linear in the 10 to 700 aM DNA concentration range. Graphical abstractSchematic of a voltammetric method for the determination of attomolar levels of target DNA. It is based on molecular beacon mediated circular strand displacement and rolling circle amplification strategies. Under optimal experimental conditions, the assay displays an ultrahigh sensitivity with a 2.6 aM detection limit and excellent selectivity.

中文翻译：

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使用分子信标介导的环状链置换和滚环扩增法测定乙型肝炎病毒基因组序列的阿托摩尔水平

摘要作者描述了一种用于测定具有源自乙型肝炎病毒 (HBV) 基因组序列的单链 DNA (ssDNA) 寡核苷酸的电化学方法。它正在利用由分子信标 (MB) 介导的环状链置换 (CSD) 和滚环扩增 (RCA) 策略。该 ssDNA 与固定在金电极表面上的 MB 的环部分杂交，而引物 DNA 也与 MB 的其余部分 DNA 序列杂交。这会触发 MB 介导的 CSD。然后启动 RCA 以产生具有多个串联重复序列的长 DNA 链，这导致电化学探针亚甲蓝的差分脉冲伏安响应在 -0.24 V 的相当低的工作电位（vs.银/氯化银）。在最佳实验条件下，该测定显示出超高灵敏度（检测限为 2.6 aM）和出色的选择性。响应在 10 到 700 aM DNA 浓度范围内呈线性。用于测定目标 DNA 的阿托摩尔水平的伏安法示意图。它基于分子信标介导的环状链置换和滚环扩增策略。在最佳实验条件下，该测定显示出超高灵敏度，检测限为 2.6 aM，并具有出色的选择性。用于测定目标 DNA 的阿托摩尔水平的伏安法示意图。它基于分子信标介导的环状链置换和滚环扩增策略。在最佳实验条件下，该测定显示出超高灵敏度，检测限为 2.6 aM，并具有出色的选择性。用于测定目标 DNA 的阿托摩尔水平的伏安法示意图。它基于分子信标介导的环状链置换和滚环扩增策略。在最佳实验条件下，该测定显示出超高灵敏度，检测限为 2.6 aM，并且具有出色的选择性。