In this work, we designed a facile and label-free electrochemical biosensor based on intrinsic topological insulator (TI) Bi₂Se₃ and peptide for the detection of immune checkpoint molecules. With topological protection, Bi₂Se₃ could have robust surface states with low electronic noise, which was beneficial for the stable and sensitive electron transport between electrode and electrolyte interface. The peptides are easily synthesized and chemically modified, and have good biocompatibility and bioavailability, which is a suitable candidate as the recognition units for immune checkpoint molecules. Therefore, the peptide/Bi₂Se₃ was developed as a suitable working electrode for the electrochemical biosensor. The basic performance of the designed peptide/Bi₂Se₃ biosensor was investigated to determine the Anti-HA Tag Antibody and PD-L1 molecules. The linear detection range was from 3.6 × 10⁻¹⁰ mg mL⁻¹ to 3.6 × 10⁻⁵ mg mL⁻¹, and the detection limit was 1.07 × 10⁻¹¹ mg mL⁻¹. Moreover, the biosensor also displayed good selectivity and stability.

在这项工作中，我们设计了一种基于固有拓扑绝缘体 (TI) Bi ₂ Se ₃和肽的简便且无标记的电化学生物传感器，用于检测免疫检查点分子。通过拓扑保护，Bi ₂ Se ₃可以具有稳健的表面态和低电子噪声，这有利于电极和电解质界面之间稳定和灵敏的电子传输。该肽易于合成和化学修饰，具有良好的生物相容性和生物利用度，是免疫检查点分子识别单元的合适候选者。因此，肽/Bi ₂ Se ₃被开发为电化学生物传感器的合适工作电极。对设计的肽/Bi ₂ Se ₃生物传感器的基本性能进行了研究，以确定抗 HA 标签抗体和 PD-L1 分子。线性检测范围为3.6×10 ^-10  mg mL ^-1至3.6×10 ^-5  mg mL ^-1，检测限为1.07×10 ^-11  mg mL ^-1。此外，该生物传感器还表现出良好的选择性和稳定性。