Abstract A novel electrochemiluminescence (ECL) biosensing interface for Hg2+ analysis was constructed based on the enhanced ECL signal from CdS quantum dots by reduced graphene oxide-Au nanoparticles (RGO-AuNPs) nanocomposites. RGO-AuNPs were prepared by the heat-treatment of graphene oxide and HAuCl4 solution under alkaline environment. The prepared RGO-AuNPs composites were dispersed in N,N-dimethylformamide and dropped onto the surface of glassy carbon electrode (GCE). Double-stranded DNA modified with amino at one end was then immobilized on the RGO-AuNPs/GCE surface in the presence of 1-pyrenebutyric acid N-hydroxysuccinimide linker, following which the avidin-modified CdS quantum dots were linked to double-stranded DNA labeled with biotin at another end through the formation of biotin–avidin complex. The excellent electrical conductivity of RGO-AuNPs nanocomposites and the high charge transfer efficiencies of the double-stranded DNA with T–Hg2+–T complex, which produced high-intensity electron transfer interface and improved the sensitivity of the biosensor. After Hg2+ was added into the detection solution, the increased ECL signals showed good correlation with Hg2+ concentration. The linear range of the sensor was 5.0 × 10−13–1.0 × 10−9 M with a detection limit of 2.0 × 10−13 M. This ECL biosensor showed satisfactory results when used for detecting Hg2+ in real lake water.

中文翻译：

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使用还原氧化石墨烯-Au 纳米复合材料和 CdS 量子点制备用于 Hg 2+ 检测的高强度电子转移电化学发光界面

摘要 基于还原氧化石墨烯-金纳米粒子 (RGO-AuNPs) 纳米复合材料来自 CdS 量子点的增强 ECL 信号，构建了一种用于 Hg2+ 分析的新型电化学发光 (ECL) 生物传感界面。RGO-AuNPs 是通过在碱性环境下对氧化石墨烯和 HAuCl4 溶液进行热处理来制备的。将制备的 RGO-AuNPs 复合材料分散在 N,N-二甲基甲酰胺中并滴在玻璃碳电极 (GCE) 的表面上。然后在 1-芘丁酸 N-羟基琥珀酰亚胺接头存在下，将一端氨基修饰的双链 DNA 固定在 RGO-AuNPs/GCE 表面，然后将抗生物素蛋白修饰的 CdS 量子点连接到双链 DNA通过形成生物素-抗生物素蛋白复合物在另一端用生物素标记。RGO-AuNPs 纳米复合材料的优异导电性和双链 DNA 与 T–Hg2+–T 复合物的高电荷转移效率，产生了高强度的电子转移界面，提高了生物传感器的灵敏度。检测液中加入Hg2+后，增加的ECL信号与Hg2+浓度显示出良好的相关性。传感器的线性范围为 5.0 × 10-13-1.0 × 10-9 M，检测限为 2.0 × 10-13 M。该 ECL 生物传感器在用于检测真实湖水中的 Hg2+ 时显示出令人满意的结果。增加的 ECL 信号与 Hg2+ 浓度显示出良好的相关性。传感器的线性范围为 5.0 × 10-13-1.0 × 10-9 M，检测限为 2.0 × 10-13 M。该 ECL 生物传感器在用于检测真实湖水中的 Hg2+ 时显示出令人满意的结果。增加的 ECL 信号与 Hg2+ 浓度显示出良好的相关性。传感器的线性范围为 5.0 × 10-13-1.0 × 10-9 M，检测限为 2.0 × 10-13 M。该 ECL 生物传感器在用于检测真实湖水中的 Hg2+ 时显示出令人满意的结果。