Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz 51666-16471, Iran; Departamento de Química Analítica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain.
Departamento de Química Analítica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain.
Anal Chim Acta. 2018 Jun 29;1011:28-34. doi: 10.1016/j.aca.2018.01.039. Epub 2018 Feb 3.
A new label-free electrochemical immunosensor is constructed for the selective and sensitive determination of the clinically relevant biomarker receptor tyrosine kinase (AXL) in human serum. The disposable immunosensing platform is prepared by immobilization of the specific anti-AXL antibody onto amine functionalized graphene quantum dots (fGQDs)-modified screen-printed carbon electrodes (SPCEs). The affinity reactions were monitored by measuring the decrease in the differential pulse voltammetric (DPV) response of the redox probe Fe(CN). All the experimental variables involved in the preparation of the modified electrodes and in the immunosensor performance were optimized. The as prepared immunosensor exhibits an improved analytical performance with respect to other electrochemical immunosensors reported so far, with a wider range of linearity and a lower detection limit, 0.5 pg mL, which is more than one hundred thousand times lower than the established cut-off value for heart failure (HF) diagnosis in serum (71 ng mL). The developed immunosensor was successfully applied to the determination of the endogenous content of AXL in serum of HF patients without any matrix effect observed after just a sample dilution.
一种新型的无标记电化学免疫传感器被构建用于选择性和灵敏地测定人血清中临床相关的生物标志物受体酪氨酸激酶（AXL）。通过将特异性抗 AXL 抗体固定在胺功能化的石墨烯量子点（fGQDs）修饰的丝网印刷碳电极（SPCE）上，制备了一次性免疫传感平台。通过测量氧化还原探针 Fe（CN）的差分脉冲伏安（DPV）响应的降低来监测亲和反应。优化了制备修饰电极和免疫传感器性能所涉及的所有实验变量。与迄今为止报道的其他电化学免疫传感器相比，所制备的免疫传感器具有改进的分析性能，具有更宽的线性范围和更低的检测限，为 0.5pg/mL，比血清心力衰竭（HF）诊断中建立的截止值低一百万倍以上（71ng/mL）。所开发的免疫传感器成功地应用于测定 HF 患者血清中内源性 AXL 的含量，在仅进行样品稀释后，未观察到任何基质效应。
