The analysis of protein biomarkers is of great importance in the diagnosis of diseases. Although many convenient and low‐cost electrochemical approaches have been extensively investigated, they are not sensitive enough in the detection of protein biomarkers with low concentrations in physiological environments. Here, this study reports a novel organic‐electrochemical‐transistor‐based biosensor that can successfully detect cancer protein biomarkers with ultrahigh sensitivity. The devices are operated by detecting electrochemical activity on gate electrodes, which is dependent on the concentrations of proteins labeled with catalytic nanoprobes. The protein sensors can specifically detect a cancer biomarker, human epidermal growth factor receptor 2, down to the concentration of 10⁻¹⁴ g mL⁻¹, which is several orders of magnitude lower than the detection limits of previously reported electrochemical approaches. Moreover, the devices can successfully differentiate breast cancer cells from normal cells at various concentrations. The ultrahigh sensitivity of the protein sensors is attributed to the inherent amplification function of the organic electrochemical transistors. This work paves a way for developing highly sensitive and low‐cost biosensors for the detection of various protein biomarkers in clinical analysis in the future.

中文翻译：

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有机电化学晶体管高度灵敏地检测蛋白质生物标志物

蛋白质生物标志物的分析在疾病的诊断中非常重要。尽管已经广泛研究了许多方便且低成本的电化学方法，但它们在生理环境中检测低浓度的蛋白质生物标志物时不够灵敏。在这里，这项研究报告了一种新型的基于有机电化学晶体管的生物传感器，该传感器可以超高灵敏度成功地检测出癌症蛋白质生物标志物。通过检测栅电极上的电化学活性来操作设备，电化学活性取决于用催化纳米探针标记的蛋白质的浓度。蛋白质传感器可以特异性地检测低至10 ^-14 g mL ^-1浓度的癌症生物标记物人类表皮生长因子受体2。，比以前报道的电化学方法的检测限低几个数量级。而且，该设备可以成功地以各种浓度将乳腺癌细胞与正常细胞区分开。蛋白质传感器的超高灵敏度归因于有机电化学晶体管的固有放大功能。这项工作为开发高度灵敏，低成本的生物传感器奠定了基础，该传感器可在未来的临床分析中检测各种蛋白质生物标志物。