Fabrication of Electrochemical Immunosensor for Detection of Interleukin 8 Biomarker via Layer-by-layer Self-assembly Process on Cost-effective Fluorine Tin Oxide Electrode

A highly sensitive impedimetric immunosensor for the determination of interleukin 8 (IL 8) cancer biomarker was fabricated via simple fabrication process. A silane agent with isocyanate groups, 3-(triethoxysilyl)propyl isocyanate (IPTES), were utilized for binding of IL 8 antigen specific antibodies and self-assembled on the fluorine tin oxide (FTO) substrate with a standard silanization chemistry. Under optimum experimental conditions, the designed immunosensor had a wide linear detection range of 0.02–4 pg/mL, a low limit of detection of 11.9 fg/mL and a high sensitivity of 4.42 kΩ pg⁻¹ mL cm⁻². The designed biosensor displayed high reproducibility and repeatability, good selectivity against interference biomarkers.