Oligonucleotide-modulated photocurrent enhancement of a tetracationic porphyrin for label-free homogeneous photoelectrochemical biosensing
Oligonucleotide-modulated photocurrent enhancement of a tetracationic porphyrin for label-free homogeneous photoelectrochemical biosensing
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寡核苷酸调制的四阳离子卟啉光电流增强用于无标记均质光电化学生物传感
DOI：
10.1016/j.bios.2018.08.071
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发表时间：
2018
影响因子：
12.6
通讯作者：
Li Feng
中科院分区：
文献类型：
--
作者：
Hong Qing;Ge Lei;Wang Wenxiao;Liu Xiaojuan;Li Feng
这项工作报告了一种基于四价卟啉（在此表示为TMPyP）吸附到1-萘磺酸根阴离子（NS−）接枝的氧化铟锡电极（表示为TMPyP-NS−-ITO）上的无标记均相光电化学（PEC）生物传感平台的首次演示，该平台产生稳定和快速的光电流响应。我们发现，当NS−-ITO电极在TMPyP吸附之前经受单链寡核苷酸（ssON）时，从所得到的对寡核苷酸具有高特异性的TMPyP-ssON-NS−-ITO电极观察到光电流强度的显著增强。进行了一系列的调查，以了解这种磷脂调制的光电流增强现象的机制。此外，对这种强大的光电流增强机制的研究被成功扩展到开发一个信号-均质PEC生物传感平台，作为概念验证，通过明智且兼容的工程信号转导策略，用于无标记M.SssI甲基转移酶活性分析发夹形寡核苷酸探针、限制性内切酶HpaII和核酸外切酶I。该传感器对M.SssI甲基转移酶具有灵敏的响应，检测限为3.5 mU/mL，线性范围为0.01 ~ 120 U/mL。此外，我们还表明，我们的均相PEC生物传感平台也可用于筛选甲基转移酶抑制剂。因此，这项工作将提供一个独特的范例，多功能的均相PEC生物传感平台，可用作潜在的强大工具，朝着创新的无标记生物分析的目的。
This work reports the first demonstration of an oligonucleotide-modulated label-free homogeneous photoelectrochemical (PEC) biosensing platform based on the adsorption of tetracationic porphyrin (denoted as TMPyP here) onto 1-naphthalenesulfonate anion (NS−)-grafted indium tin oxide electrode (denoted as TMPyP-NS−-ITO), which generates a stable and rapid photocurrent response. We found that when NS−-ITO electrode was subjected to single-stranded oligonucleotide (ssON) before TMPyP adsorption, a remarkable enhancement of photocurrent intensity was observed from the resulted TMPyP-ssON-NS−-ITO electrode with high specificity towards oligonucleotide. A series of investigations were carried out to understand the mechanism of this oligonucleotide-modulated photocurrent enhancement phenomenon. Moreover, the studies of this robust photocurrent enhancement mechanism was successfully extended to develop a signal-on homogeneous PEC biosensing platform for, as a proof-of-concept, label-free M.SssI methyltransferase activity analysis through a judiciously and compatibly engineered signal transduction strategy consisted of hairpin-shaped oligonucleotide probe, restriction endonucleaseHpaII, and Exonuclease I. The rationally designed homogeneous PEC biosensor exhibit sensitive PEC response toward M.SssI methyltransferase with a low detection limit of 3.5 mU/mL and a wide linear range from 0.01 to 120 U/mL. Additionally, we show that our homogeneous PEC biosensing platform can be also utilized to screen methyltransferase inhibitors. Therefore, this work will provide a distinctive paradigm for versatile homogeneous PEC biosensing platform that can be used as potential powerful tool toward innovative label-free bioanalytical purposes.