As a primary building block for protein synthesis, l-arginine (l-Arg) is also a precursor for the synthesis of important metabolites, and is involved in various physiological and pathophysiological processes. l-Arg is a potential biomarker in clinical diagnosis and nutritional status assessment, making it valuable to quantify and monitor this biomolecule. In this study, peptide aptamers that specifically interact with l-Arg were identified by high-throughput molecular docking, and the binding capacities between the synthesized peptide aptamers and l-Arg were then measured by isothermal titration calorimetry. We hypothesized that the peptide aptamer with the greatest binding capacity could be used as the recognition element in a biosensor. A chemosynthetic peptide aptamer modified with mercaptan and spacer units (thioctic acid-GGGG-FGHIHEGY) was thus used to construct label-free electrochemical impedimetric biosensors for l-Arg based on gold electrodes. The optimum biosensor showed good sensitivity to l-Arg with a linear range of 0.1 pM–0.1 mM, and the calculated limit of detection (three times the signal-to-noise ratio) was 0.01 pM. Interference studies and assays of diluted serum samples were also carried out, and satisfactory results obtained. In conclusion, a potential method of peptide aptamer screening and biosensor fabrication for detecting small biological molecules was demonstrated.

作为蛋白质合成的主要组成部分，1-精氨酸（1 - Arg ）也是重要代谢物合成的前体，并参与各种生理和病理生理过程。l -Arg是临床诊断和营养状况评估中的潜在生物标志物，因此对量化和监测该生物分子具有重要意义。在这项研究中，通过高通量分子对接鉴定了与1- Arg特异性相互作用的肽适体，以及合成的肽适体与I -Arg之间的结合能力。然后通过等温滴定热法测量-Arg。我们假设具有最大结合能力的肽适体可用作生物传感器中的识别元件。因此，用硫醇和间隔基单元修饰的化学合成肽适体（硫辛酸-GGGG-FGHIHEGY）用于构建基于金电极的1 -Arg的无标记电化学阻抗生物传感器。最佳的生物传感器显示出对l的良好敏感性-Arg的线性范围为0.1 pM–0.1 mM，计算出的检出限（信噪比的三倍）为0.01 pM。还进行了稀释血清样品的干扰研究和测定，并获得了满意的结果。总之，展示了一种潜在的肽适体筛选和生物传感器制造方法，用于检测小的生物分子。