This work gathers and presents three lectin-based impedimetric biosensors for the selective detection of specific aberrant cancer-associated O-glycans, namely STn, Tn and T antigens. These truncated glycans are well-established pan-carcinoma biomarkers that are synthesized by tumour cells during protein glycosylation. Glycoproteins carrying these aberrant glycans are then secreted into the blood stream, where they can be detected as cancer biomarkers. Detection of aberrant O-glycoproteins in serum can be successfully performed by using lectin biosensors, as lectins show high selectivity towards particular glycan structures. Lectins are immobilized on the sensor surface, maintaining intact their binding ability towards the glycans present in the sample. For these three biosensors, Sambucus nigra agglutinin, Vicia villosa agglutinin and Arachis hypogeae agglutinin were used as biorecognition elements, with specificity for STn, Tn and T antigens, respectively. The binding event between each lectin and the corresponding aberrant O-glycan was monitored by electrochemical impedance spectroscopy, measuring the increase in the biosensor’s impedance after incubating the samples. The increase in impedance was related to the lectin-glycan complex formation. The performance of the developed biosensors, prepared on screen printed gold electrodes, was evaluated, namely in what concerns selectivity, sensitivity, limit of detection, reproducibility and robustness. Furthermore, a thorough validation was carried out by analyzing serum samples from cancer patients and from healthy donors. Results showed that the three biosensors could efficiently discriminate between controls and patients. Moreover, by analyzing the same samples with the different biosensors, distinct glycosylation profiles could be observed.
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机译：这项工作收集并呈现了三种基于素的阻抗生物传感器，用于选择性检测特异性异常癌症相关的O-聚糖，即STN，TN和T抗原。这些截短的聚糖是成熟的泛癌生物标志物，其在蛋白质糖基化期间被肿瘤细胞合成。然后将携带这些异常聚糖的糖蛋白分泌到血流中，在那里它们可以被检测为癌症生物标志物。通过使用凝集素生物传感器，可以成功地进行血清中异常O-糖蛋白的检测，因为凝集素显示出对特定聚糖结构的高选择性。凝集素固定在传感器表面上，保持完整的它们的结合能力朝向样品中存在的聚糖。对于这三种生物传感器，Sambucus nigra alglutinin，vicia villosa alglutinin和arachis hypogeae alglutinin被用作生物识别元素，分别具有STN，Tn和T抗原的特异性。通过电化学阻抗光谱监测每种凝集素和相应的异常O-聚糖之间的结合事件，测量生物传感器和rsquo的增加。在孵育样品后的阻抗。阻抗的增加与凝集素 - 聚糖复合物形成有关。在筛选印刷金电极上制备的发达生物传感器的性能，即在选择性，灵敏度，检测，再现性和鲁棒性极限时涉及什么。此外，通过分析来自癌症患者和健康供体的血清样本来进行彻底验证。结果表明，三种生物传感器可以有效地区分对照和患者。此外，通过分析具有不同生物传感器的相同样品，可以观察到不同的糖基化曲线。
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