Organic photoelectrochemical transistor (OPECT) biosensing is a new concept that combines photoelectrochemical and organic electrochemical transistor biosensing. It reduces background noise and combines both signal amplification for low abundance biomolecule detection. In this work, an OPECT biosensor for the detection of fat mass and obesity-associated protein (FTO) was constructed, in which ZnSe/Bi2MoO6 was chosen as the gate material, hm6ARNA (containing N6-methyladenine RNA sequence) as the target molecule, and hydroquinone as the electron donor. Under FTO oxidation induced RNA demethylation, the formation of hemin loaded with G-quadruplex on the electrode surface was triggered. With the catalysis of hemin-based DNAzyme towards the oxidation reaction caused by H2O2 towards hydroquinone and ZnSe, the electron donor was consumed and ZnSe was oxidized in situ to form SeO2 which reduced the photo-anodic response. The variation of the gate effectively gated the state of the channel polymer thus producing different channel current responses, a process that was closely related to the content of FTO. In addition, the effects of rhein and potassium perfluorohexanesulfonate on FTO activity were also investigated in this experiment, with IC50 values of 10.62 μM, 31.28 mg/L respectively.

中文翻译：

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基于ZnSe/Bi2MoO6异质结原位氧化的反应介导双信号抑制门控有机光电化学晶体管生物传感器用于FTO活性检测


有机光电化学晶体管（OPECT）生物传感是光电化学和有机电化学晶体管生物传感相结合的新概念。它降低了背景噪音，并结合了信号放大功能，用于低丰度生物分子检测。本工作构建了一种用于检测脂肪量和肥胖相关蛋白（FTO）的OPECT生物传感器，其中选择ZnSe/Bi2MoO6作为门材料，hm6ARNA（含有N6-甲基腺嘌呤RNA序列）作为目标分子，和对苯二酚作为电子给体。在 FTO 氧化诱导的 RNA 去甲基化作用下，触发了电极表面负载 G-四链体的氯化血红素的形成。在基于血红素的 DNAzyme 的催化下，H2O2 引起对苯二酚和 ZnSe 的氧化反应，电子供体被消耗，ZnSe 被原位氧化形成 SeO2，从而降低了光阳极响应。栅极的变化有效地控制了通道聚合物的状态，从而产生不同的通道电流响应，这一过程与FTO的含量密切相关。此外，本实验还考察了大黄酸和全氟己磺酸钾对FTO活性的影响，IC50值分别为10.62 μM、31.28 mg/L。