Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung, Taiwan.
Department of Anatomy, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
Biosens Bioelectron. 2018 Sep 30;116:100-107. doi: 10.1016/j.bios.2018.05.002. Epub 2018 May 5.
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-CNH, showed a better sensitivity than that with a longer linker, mannose-CNH. GCE modified with amino-functionalized galactose derivative, galactose-CNH, 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)]/[Fe(CN)]. The charge transfer resistance in the Nyquist plots linearly depended on the concentration of MDA-MB-231 cells (1.0 × 10-1.0 × 10 cells mL, with 10 cells mL being the lower detection limit). Introducing 0.1% polyethylene glycol-200 (PEG-200) was able to prevent the interference caused by 1.0 × 10 HEK-293T cells mL, a non-cancer cell line (control).
一种无标记和超灵敏的电化学阻抗细胞传感器被开发出来，通过甘露糖玻璃碳电极 (GCE) 与靶细胞表面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 GCE 通过在 GCE 表面电接枝氨基功能化的甘露糖衍生物来制备，其中电极的碳原子与甘露糖衍生物的氨基之间形成共价键。荧光显微镜表明，该电极对 MDA-MB-231 细胞具有特异性，对捕获的活细胞具有良好的生物相容性。具有较短烷基接头的衍生物甘露糖-CNH 比具有较长接头的衍生物甘露糖-CNH 具有更好的灵敏度。用氨基功能化的半乳糖衍生物半乳糖-CNH 修饰的 GCE 对 MDA-MB-231 细胞的检测没有功能。通过循环伏安法中峰分离的变化或电化学阻抗谱（奈奎斯特图）中电荷转移电阻的变化，确定了甘露糖 GCE 与 Con A（一种甘露糖结合凝集素）或过表达甘露糖受体的 MDA-MB-231 乳腺癌细胞之间的特异性相互作用含有可逆氧化还原对 [Fe(CN)]/[Fe(CN)] 的电解质。奈奎斯特图中的电荷转移电阻与 MDA-MB-231 细胞的浓度呈线性关系（1.0×10-1.0×10 细胞/mL，检测下限为 1.0×10 个细胞/mL）。引入 0.1%的聚乙二醇-200（PEG-200）能够防止 1.0×10 HEK-293T 细胞/mL（对照，非癌细胞系）引起的干扰。
