A tetrahedral DNA probe can effectively overcome the steric effects of a single-stranded probe to obtain well-controlled density and minimize nonspecific adsorption. Herein, a highly sensitive electrochemical biosensor is fabricated for determination of protein using a tetrahedral DNA probe and rolling circle amplification (RCA). N- and P-co-doped graphene (NP-rGO) is prepared, and AuNPs are then electrodeposited on it for DNA probe immobilization. Benefitting from the synergistic effects of the excellent electrical conductivity of NP-rGO, the stability of the tetrahedral DNA probe and the signal amplification of RCA, the biosensor achieves a low limit of 3.53 × 10-14 M for thrombin and a wide linear range from 1 × 10-13 to 1 × 10-7 M. This study provides a sensitive and effective method for the detection of protein in peripheral biofluids, and paves the way for future clinical diagnostics and treatment of disease. Graphical abstract.

中文翻译：

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基于四面体DNA探针，N和P共掺杂的石墨烯以及滚环扩增的蛋白质高度灵敏电化学生物传感器。

四面体DNA探针可以有效克服单链探针的空间效应，从而获得良好控制的密度并使非特异性吸附最小化。在此，制造高灵敏度的电化学生物传感器，以使用四面体DNA探针和滚环扩增（RCA）测定蛋白质。制备了N和P共掺杂的石墨烯（NP-rGO），然后将AuNPs电沉积在其上以固定DNA探针。得益于NP-rGO出色的电导率，四面体DNA探针的稳定性和RCA的信号放大的协同效应，该生物传感器的凝血酶最低限度为3.53×10-14 M，线性范围为1×10-13至1×10-7M。这项研究提供了一种灵敏有效的方法来检测周围生物流体中的蛋白质，为未来的临床诊断和治疗铺平了道路。图形概要。