Background: Biomarkers are very important disease-related biomolecules which should be
analyzed sensitive and selective in related physiological fluids or tissues. Tumor necrosis factor-α is a
type of cytokine which plays vitlly important roles in different methabolic pathways such as cell death,
survival, differentiation, proliferation and migration, and infectious and inflammatory diseases including
rheumatoid arthritis, diabetes.
Objective: In this study, it was aimed to develop a reliable tool based on star-shaped poly(glycidyl
methacrylate) polymer coated disposable indium tin oxide electrode for determination of Tumor necrosis
factor-α, an important disease biomarker.
Methods: Star shaped polymer was used as an interface material for anti- Tumor necrosis factor α antibodies
immobilization. The antibodies were immobilized covalently onto polymer coated indium tin
oxide electrode. Electrochemical impedance spectroscopy and cyclic voltammetry techniques were
used for all electrochemical measurements.
Results: The suggested immunosensor exhibited a linear range between 0.02 and 4 pg/mL Tumor necrosis
factor-α, and the detection limit was found as 6 fg/mL. Scanning electron microscopy and atomic
force microscopy were used for electrode surface characterization. In addition, the suggested immunosensor
was used for Tumor necrosis factor-α sensing in human serum samples. The results displayed
recoveries between 97.07 and 100.19%. Moreover, this immunosensor had a simple fabrication
procedure and a long storage-stability.
Conclusion: A new biosensor based on a Star shaped polymer for the ultra sensitive determination of a
biomarker Tumor necrosis factor-α was developed. The biosensor presented excellent repeatability and
reproducubility, and also wide calibration range for Tumor necrosis factor- α.