Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, Ministry of Education, Shandong Key Laboratory of Biochemical Analysis, Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China.
ACS Appl Mater Interfaces. 2021 May 5;13(17):20388-20396. doi: 10.1021/acsami.1c04933. Epub 2021 Apr 20.
A universal strategy for the construction of ratiometric antifouling electrochemical biosensors was developed based on multifunctional peptides and 2D nanomaterial MXene loaded with gold nanoparticles (AuNPs) and methylene blue (MB). The nanocomposite of MXene loaded with AuNPs and MB (MXene-Au-MB) exhibited excellent conductivity, where the AuNPs were able to capture biomolecules containing sulfhydryl terminus, and the MB molecules were used to generate electrochemical signal. The MXene-Au-MB was fixed on the electrode surface by Nafion, and the anchored peptide captured the electrochemical signal probe carboxyl-modified ferrocene (Fc) to construct an electrochemical biosensor. The multifunctional peptide containing the anchoring, antifouling, and recognizing sequences endowed the sensing surface not only the assaying function but also the capability to resist nonspecific adsorption from complex samples. In the biosensing system, with the increase in the target concentration, the electrochemical signal of MB remained constant, whereas the electrochemical signal of Fc gradually decreased, and the ratiometric detection strategy greatly improved the accuracy of the biosensor. In the presence of a model target prostate-specific antigen (PSA), the recognizing sequence was recognized and cleaved, and the ratiometric signal of Fc and MB indicated the concentration of PSA accurately and sensitively, with a detection range from 5 pg/mL to 10 ng/mL and a limit of detection of 0.83 pg/mL. Electrochemical biosensors based on the MXene-Au-MB and multifunctional peptides possessed high selectivity, accuracy, and sensitivity even in real complex biological samples because of the excellent antifouling ability of the peptide. More importantly, the assaying of other targets can be easily realized with a similar biosensing strategy by changing the recognition sequence of the multifunctional peptide, and the detection of thrombin (TB) has also been achieved in this work.
基于多功能肽和负载金纳米粒子 (AuNPs) 和亚甲蓝 (MB) 的二维纳米材料 MXene，开发了一种用于构建比率型抗污染电化学生物传感器的通用策略。负载 AuNPs 和 MB 的 MXene 纳米复合材料 (MXene-Au-MB) 表现出优异的导电性，其中 AuNPs 能够捕获含有巯基末端的生物分子，而 MB 分子则用于产生电化学信号。MXene-Au-MB 通过 Nafion 固定在电极表面，锚定肽捕获电化学信号探针羧基修饰的二茂铁 (Fc) 以构建电化学生物传感器。含有锚固、抗污染和识别序列的多功能肽不仅赋予传感表面分析功能，还赋予其抵抗复杂样品中非特异性吸附的能力。在生物传感系统中，随着目标浓度的增加，MB 的电化学信号保持不变，而 Fc 的电化学信号逐渐降低，比率检测策略极大地提高了生物传感器的准确性。在存在模型靶标前列腺特异性抗原 (PSA) 的情况下，识别序列被识别和切割，Fc 和 MB 的比率信号准确而敏感地指示 PSA 的浓度，检测范围为 5 pg/mL 至 10 ng/mL，检测限为 0.83 pg/mL。基于 MXene-Au-MB 和多功能肽的电化学生物传感器具有出色的抗污染能力，即使在真实复杂的生物样品中也具有高选择性、准确性和灵敏度。更重要的是，通过改变多功能肽的识别序列，可以轻松实现其他目标的检测，并且在这项工作中还实现了对凝血酶 (TB) 的检测。
