State Key Laboratory Base of Eco-chemical Engineering; Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE; College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China.
State Key Laboratory Base of Eco-chemical Engineering; Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE; College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China.
Biosens Bioelectron. 2021 Oct 15;190:113466. doi: 10.1016/j.bios.2021.113466. Epub 2021 Jun 24.
The development of antifouling biosensors capable of detecting biomarkers at low concentrations in complex bio-fluids with many interference components is of great importance in the diagnosis and treatment of diseases. Certain zwitterionic peptides composed of natural L-amino acids have been used for the construction of low fouling biosensors and demonstrated excellent antifouling performances, but they are prone to enzymatic degradation in biological media, such as serum that contains a variety of enzymes. In this work, a novel antifouling peptide with the sequence of cppPPEKEKEkek was designed, and three unnatural D-amino acids were set at both ends of the peptide to enhance its tolerance to enzymatic degradation. An electrochemical biosensor was constructed by coupling the antifouling peptide with a conducting polymer polyaniline (PANI) to achieve accurate detection of alpha-fetoprotein (AFP) in clinical samples. Owing to the presence of the designed peptide with partial D-amino acids (pD-peptide), the biosensing interface showed significantly high antifouling performance and enhanced stability in human serum. Meanwhile, the pD-peptide based biosensor exhibited high sensitivity toward the target AFP, with the linear range from 0.1 fg mL to 1.0 ng mL and the limit of detection of 0.03 fg mL (S/N = 3). This strategy of enhancing the stability (tolerance to enzymolysis) of antifouling peptides in biological samples provided an effective way to develop antifouling biosensors for practical applications.
开发能够在含有多种干扰成分的复杂生物流体中检测低浓度生物标志物的抗污染生物传感器在疾病的诊断和治疗中具有重要意义。某些由天然 L-氨基酸组成的两性离子肽已被用于构建低污染生物传感器，并表现出优异的抗污染性能，但它们在生物介质中（如含有多种酶的血清）容易被酶降解。在这项工作中，设计了一种具有 cppPPEKEKEkek 序列的新型抗污染肽，并在肽的两端设置了三个非天然 D-氨基酸，以增强其对酶降解的耐受性。通过将抗污染肽与导电聚合物聚苯胺（PANI）偶联，构建了一种电化学生物传感器，实现了对临床样本中甲胎蛋白（AFP）的准确检测。由于存在部分 D-氨基酸（pD-肽）的设计肽，生物传感界面在人血清中表现出显著的高抗污染性能和增强的稳定性。同时，基于 pD-肽的生物传感器对目标 AFP 表现出高灵敏度，线性范围为 0.1 fg mL 至 1.0 ng mL，检测限为 0.03 fg mL（S/N = 3）。这种增强抗污染肽在生物样品中稳定性（耐酶解性）的策略为开发实用的抗污染生物传感器提供了一种有效途径。
