Abstract We had reported an electrochemical assay for dopamine with high sensitivity and selectivity based on dual molecular recognition strategy and amplification of DNA–Au bio–bar codes. In this assay, carbon nanotubes were first immobilized on the glass carbon electrode surface. Subsequently, a boronic acid-functionalized pyrene probe was self-assembled on the sidewalls of carbon nanotubes via π–π stacking interactions as a capture probe. 3,3′-Dithiodipropionic acid di(N-hydroxysuccinimide ester) (DSP) and double strands DNA functionalized AuNPs (DSP/AuNPs/dsDNA) were designed as signal probes and characterized by transmission electron microscopy and spectroscopic techniques. Upon the binding of dopamine with boronic acid followed by DSP/AuNPs/dsDNA, the AuNPs were captured on the electrode surface to enhance the signal. RuHex, an electroactive complex, which could bind to the anionic phosphate of DNA strands through electrostatic interaction, serves as signaling transducer. Signal amplification and dual recognition were used to quantify dopamine concentration from 30 pM to 30 nM, with a detection limit of 18 pM. Other small molecules could be measured by this assay after modification with differential recognition molecules.

中文翻译：

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基于DNA-Au生物条形码扩增的多巴胺高灵敏电化学检测双分子识别策略

摘要 我们报道了一种基于双分子识别策略和 DNA-Au 生物条形码扩增的高灵敏度和高选择性的多巴胺电化学检测方法。在该测定中，首先将碳纳米管固定在玻璃碳电极表面上。随后，硼酸功能化芘探针作为捕获探针通过π-π堆积相互作用自组装在碳纳米管的侧壁上。3,3'-二硫代二丙酸二（N-羟基琥珀酰亚胺酯）（DSP）和双链DNA功能化AuNPs（DSP/AuNPs/dsDNA）被设计为信号探针，并通过透射电子显微镜和光谱技术进行表征。在多巴胺与硼酸结合后，再结合 DSP/AuNPs/dsDNA，AuNPs 被捕获在电极表面以增强信号。RuHex，一种电活性复合物，可以通过静电相互作用与 DNA 链的阴离子磷酸盐结合，作为信号转导器。信号放大和双重识别用于量化多巴胺浓度从 30 pM 到 30 nM，检测限为 18 pM。其他小分子可以在用差异识别分子修饰后通过该测定进行测量。