A label-free and ultrasensitive electrochemical impedance cytosensor was developed to specifically detect the breast cancer cells MDA-MB-231 via the interaction between the mannosyl glassy carbon electrode (GCE) and the overexpressed mannose receptors on the target cell surface. The mannosyl GCE was prepared through electrografting of the amino-functionalized mannose derivatives on GCE surface in which a covalent bond was formed between carbon of the electrode and the amino group of the mannose derivative. The fluorescent microscopy indicated that the electrode is specific for MDA-MB-231 cells, with good biocompatibility for viable captured cells. The derivative with a shorter alkyl linker, mannose-C₂NH₂, showed a better sensitivity than that with a longer linker, mannose-C₆NH₂. GCE modified with amino-functionalized galactose derivative, galactose-C₂NH₂, shows no function to the detection of MDA-MB-231 cells. The specific interaction between the mannosyl GCE and Con A (a mannose-binding lectin) or MDA-MB-231 breast cancer cells with overexpressed mannose receptors was determined through the change of peak separation in the cyclic voltammogram or the change of charge transfer resistance in the electrochemical impedance spectra (Nyquist plot) in the electrolytes containing a reversible redox couple [Fe(CN)₆]³⁻/[Fe(CN)₆]⁴⁻. The charge transfer resistance in the Nyquist plots linearly depended on the concentration of MDA-MB-231 cells (1.0 × 10–1.0 × 10⁵ cells mL⁻¹, with 10 cells mL⁻¹ being the lower detection limit). Introducing 0.1% polyethylene glycol-200 (PEG-200) was able to prevent the interference caused by 1.0 × 10³ HEK-293T cells mL⁻¹, a non-cancer cell line (control).

开发了一种无标记且超灵敏的电化学阻抗细胞传感器，以通过甘露糖基玻碳电极（GCE）与靶细胞表面上过表达的甘露糖受体之间的相互作用特异性检测乳腺癌细胞MDA-MB-231。甘露糖基GCE是通过在电极的碳与甘露糖衍生物的氨基之间形成共价键的GCE表面上电接枝氨基官能化的甘露糖衍生物而制备的。荧光显微镜检查表明该电极对MDA-MB-231细胞具有特异性，对存活的捕获细胞具有良好的生物相容性。具有较短烷基接头的甘露糖-C ₂ NH ₂的衍生物比具有较长接头的甘露糖-C的衍生物具有更好的敏感性。₆ NH ₂。用氨基官能化的半乳糖衍生物半乳糖-C ₂ NH ₂修饰的GCE对MDA-MB-231细胞的检测没有作用。甘露糖基GCE和Con A（甘露糖结合凝集素）或MDA-MB-231乳腺癌细胞与过表达甘露糖受体之间的特异性相互作用是通过改变循环伏安图中峰间距的变化或电荷转移电阻的变化来确定的。含可逆氧化还原对[Fe（CN）₆ ] ³⁻ / [Fe（CN）₆ ] ⁴⁻的电解质中的电化学阻抗谱（奈奎斯特图）。奈奎斯特图中的电荷转移电阻线性依赖于MDA-MB-231细胞的浓度（1.0×10–1.0×10 ⁵细胞mL ^-1，其中10细胞mL ^-1为检测下限）。引入0.1％聚乙二醇-200（PEG-200）能够防止由非癌细胞系（对照）1.0×10 ^3个HEK-293T细胞mL ^-1引起的干扰。