Electrochemical Immunosensor for Detection of CCR4 Cancer Biomarker in Human Serum: An Alternative Strategy for Modification of Disposable ITO Electrode.

Herein, a new strategy for the fabrication of a sensitive immunosensor capable of determination of CC Chemokine receptor 4 (CCR4) in complex serum samples is developed through the polymer modification on the disposable indium tin oxide electrode. Anti-CCR4 antibodies, which are utilized as sensing biomolecules, are covalently attached on the succinimide groups of polypyrrole polymer (PPyr-CSsg). The constructed immunosensor illustrates promising performances for the quantification of CCR4 antigen, with a linear detection range of 0.024-12 pg mL-1 and a low detection limit of 7.3 fg mL-1 , calculated at a signal-to-noise ratio of 3. In addition, the impedimetric immunosensor displays a very successful analytical performance in terms of sensitivity, selectivity, repeatability, reproducibility, and long-term stability as well as successful applicability for the accurate quantification of CCR4 in human serum samples. The constructed immunosensor is successfully used for quantification of CCR4 antigen in human serums. In addition, the immunosensor displays only 27.54% loss in its initial signal after nine weeks storage at 4 °C. Moreover, the fabricated immunosensor is economical, highly sensitive, and selective for CCR4 antigen detection, and suitable for potential application in clinical diagnosis.