An antibody transistor is a promising biosensing platform for the diagnosis and monitoring of various diseases. Nevertheless, the low concentration and short half-life of biomarkers require biodetection at the trace-molecule level, which remains a challenge for existing antibody transistors. Herein, we demonstrate a graphene field-effect transistor (gFET) with electrically oriented antibody probes (EOA-gFET) for monitoring several copies of methylated DNA. The electric field confines the orientation of antibody probes on graphene and diminishes the distance between graphene and methylated DNAs captured by antibodies, generating more induced charges on graphene and amplifying the electric signal. EOA-gFET realizes a limit of detection (LoD) of ∼0.12 copy μL^–1, reaching the lowest LoD reported before. EOA-gFET shows a distinguishable signal for liver cancer clinical serum samples within ∼6 min, which proves its potential as a powerful tool for disease screening and diagnosis.

中文翻译：

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晶体管上的电定向抗体用于监测多个甲基化 DNA 副本


抗体晶体管是一种有前途的生物传感平台，用于诊断和监测各种疾病。然而，生物标志物浓度低、半衰期短，需要在痕量分子水平上进行生物检测，这对现有抗体晶体管来说仍然是一个挑战。在此，我们展示了带有电定向抗体探针（EOA-gFET）的石墨烯场效应晶体管（gFET），用于监测甲基化DNA的多个拷贝。电场限制了石墨烯上抗体探针的方向，并缩短了石墨烯和抗体捕获的甲基化 DNA 之间的距离，在石墨烯上产生更多的感应电荷并放大电信号。 EOA-gFET 实现了 ~0.12 copy μL ^–1 的检测限 (LoD)，达到了之前报道的最低 LoD。 EOA-gFET 在~6 分钟内对肝癌临床血清样本显示出可区分的信号，这证明了其作为疾病筛查和诊断的强大工具的潜力。