An effective strategy to construct low fouling electrochemical biosensors for assaying serum biomarkers was proposed based on specially designed α-aminoisobutyric acid (Aib) incorporated peptides. The Aib-peptides were designed to be of antifouling properties, and at the same to incorporate Aib residues in their interior to enhance the hydrolytic stability. In order to construct the electrochemical biosensor, two kinds of Aib-peptides labelled with biotin were modified on the electrode surface: One with cysteine terminal for easy attachment to the electrode modified with gold nanoparticles, the other with unique terminal peptide sequence for specific binding of immunoglobulin G (IgG), and they were connected through the streptavidin-biotin affinity system. Owing to the interposition of Aib residues, the peptides as well as the constructed biosensors showed excellent antifouling performances and enhanced stability against enzymatic degradation in serum. Furthermore, the IgG biosensor constructed with the Aib-peptides displayed a very low detection limit (29.5 pg mL⁻¹) and a broad linear range (100 pg mL⁻¹ - 10 μg mL⁻¹), and it was able to assay IgG in clinical human sera with decent accuracy and reliability. This strategy provides a new path for the construction of stable antifouling biosensors based on functional peptides for practical biomarker assaying in real clinical samples.

基于专门设计的 α-氨基异丁酸 (Aib) 掺入肽，提出了一种构建用于检测血清生物标志物的低污染电化学生物传感器的有效策略。Aib 肽被设计为具有防污性能，同时在其内部加入 Aib 残基以增强水解稳定性。为了构建电化学生物传感器，在电极表面修饰了两种生物素标记的 Aib 肽：一种具有半胱氨酸末端，易于附着在金纳米粒子修饰的电极上，另一种具有独特的末端肽序列，用于特异性结合免疫球蛋白 G (IgG)，它们通过链霉亲和素-生物素亲和系统连接。由于 Aib 残基的插入，肽以及构建的生物传感器显示出优异的防污性能和增强的抗血清酶促降解的稳定性。此外，用 Aib 肽构建的 IgG 生物传感器显示出非常低的检测限（29.5 pg mL^-1 ) 和宽线性范围（100 pg mL ^-1 - 10 μg mL ^-1），并且它能够以良好的准确性和可靠性测定临床人血清中的 IgG。该策略为构建基于功能肽的稳定防污生物传感器提供了一条新途径，可用于实际临床样品中的实际生物标志物检测。