Here, a simple electrochemical biosensor was proposed based on the specific recognition between trypsin and peptide. Initially, NiCo2O4-PAMAM nanocomposite was casted on the bare electrode to achieve the electrochemical signal amplification in 0.1 mM [Ru(NH3)6]3+ solution owing to the great electronic conductivity and high electrochemical activity induced by the special structure of NiCo2O4 nanosheets (Ni3+ cations in octachedral sites of the Co3O4). Subsequently, a declined electrochemical signal was obtained when g-C3N4 labeled peptide composites were anchored on the electrode. However, after trypsin was added into solution and incubated with the biosensor, the electrochemical signal was re-promoted. Therefore, the as-synthesized biosensor could realize the sensitive detection of trypsin by virtue of the specific recognition between trypsin and peptide. As a result, the developed peptide-based exhibited a linear range from 10-10 to 10-4 mg mL-1 with an ultralow detection limit of 10-10 mg mL-1, providing sensitive analytical performance and acceptable application potential in clinical test and disease diagnosis due to its high stability, excellent selectivity, acceptable reproducibility and accurate signal output.

中文翻译：

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使用NiCo 2 O 4 纳米片和gC 3 N 4 纳米复合材料构建胰蛋白酶检测放大策略的高灵敏度肽基生物传感器

在这里，基于胰蛋白酶和肽之间的特异性识别，提出了一种简单的电化学生物传感器。最初，NiCo2O4-PAMAM 纳米复合材料被浇铸在裸电极上，以实现在 0.1 mM [Ru(NH3)6]3+ 溶液中的电化学信号放大，这是由于 NiCo2O4 纳米片的特殊结构引起的良好的电子导电性和高电化学活性（ Co3O4 八面体位点中的 Ni3+ 阳离子）。随后，当 g-C3N4 标记的肽复合物锚定在电极上时，获得了下降的电化学信号。然而，在将胰蛋白酶加入溶液中并与生物传感器一起孵育后，电化学信号被重新促进。所以，合成的生物传感器通过胰蛋白酶与肽的特异性识别，可实现对胰蛋白酶的灵敏检测。因此，开发的基于肽的线性范围为 10-10 至 10-4 mg mL-1，超低检测限为 10-10 mg mL-1，提供灵敏的分析性能和可接受的临床试验应用潜力由于其高稳定性、出色的选择性、可接受的重现性和准确的信号输出，以及疾病诊断。