An electrochemical immunosensor was developed for the determination of apo-Tf (non-iron-bound) and holo-Tf (iron-bound) using polyclonal antibody transferrin (anti-Tf) immobilized at an electrode surface as a biorecognition platform. The monitoring was based on the anti-Tf binding with both Tf forms which allows the detection of cancer cells due to the constant iron cycle and the overexpression of anti-Tf on the cancer cell surface. The immunosensor characterization was performed using electrochemical impedance spectroscopy (EIS), which evaluated the impedimetric biorecognition of the antigens-antibody by the use of K 4 Fe(CN) 6 redox group. The immunosensor was able to detect both forms of Tf in terms of charge transfer resistance ( R ct ). Analytical curves showed a limit of detection of 0.049 and 0.053 ng mL −1 for apo-Tf and holo-Tf, respectively. The immunosensor was applied to the detection of the two cancer cells A549 (lung carcinoma) and MCF-7 (breast carcinoma) and compared with BHK570, a healthy cell line. The impedimetric response of healthy cells differs significantly from that of the cancerous cells, as revealed by a Dunnett’s test in 95% confidence level—ca. 10 2 cells mL −1 —indicating the feasibility of the immunosensor to discriminate both types of cells. The indirect detection of anti-Tf based on apo-Tf and holo-Tf binding can be considered an advanced approach for cancer recognition. Graphical abstract

中文翻译：

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基于载脂蛋白和全转铁蛋白结合的癌症免疫传感器

使用固定在电极表面的多克隆抗体转铁蛋白 (anti-Tf) 作为生物识别平台，开发了一种电化学免疫传感器，用于测定 apo-Tf（非铁结合）和 Holo-Tf（铁结合）。监测基于抗 Tf 与两种 Tf 形式的结合，由于恒定的铁循环和抗 Tf 在癌细胞表面的过度表达，这允许检测癌细胞。使用电化学阻抗谱 (EIS) 进行免疫传感器表征，其通过使用 K 4 Fe(CN) 6 氧化还原基团来评估抗原-抗体的障碍生物识别。根据电荷转移电阻 (R ct )，免疫传感器能够检测两种形式的 Tf。分析曲线显示 apo-Tf 和全息 Tf 的检测限为 0.049 和 0.053 ng mL -1，分别。该免疫传感器用于检测两种癌细胞A549（肺癌）和MCF-7（乳腺癌），并与健康细胞系BHK570进行比较。健康细胞的阻抗反应与癌细胞的阻抗反应显着不同，正如 Dunnett 检验在 95% 的置信水平（约 100%）中所揭示的那样。10 2 个细胞 mL -1 — 表明免疫传感器区分两种类型细胞的可行性。基于 apo-Tf 和 Holo-Tf 结合的抗 Tf 的间接检测可以被认为是一种先进的癌症识别方法。图形概要 健康细胞的阻抗反应与癌细胞的阻抗反应显着不同，正如 Dunnett 检验在 95% 的置信水平（约 100%）中所揭示的那样。10 2 个细胞 mL -1 — 表明免疫传感器区分两种类型细胞的可行性。基于 apo-Tf 和 Holo-Tf 结合的抗 Tf 的间接检测可以被认为是一种先进的癌症识别方法。图形概要 健康细胞的阻抗反应与癌细胞的阻抗反应显着不同，正如 Dunnett 检验在 95% 的置信水平（约 100%）中所揭示的那样。10 2 个细胞 mL -1 — 表明免疫传感器区分两种类型细胞的可行性。基于 apo-Tf 和 Holo-Tf 结合的抗 Tf 的间接检测可以被认为是一种先进的癌症识别方法。图形概要