Label-free impedimetric immunosensor for ultrasensitive detection of cancer marker Murine double minute 2 in brain tissue.
The detection of cancer biomarkers is as important tool for the diagnosis and prognosis of cancer such as brain cancer. Murine double minute 2 (MDM2) has been widely studied as prognostic marker for brain tumor. Here we describe development of a new sensitive label free impedimetric immunosensor for the detection of MDM2 based on cysteamine self assembled monolayers on a clean polycrystalline Au electrode surface. The amine-modified electrodes were further functionalized with antibody using homobifunctional 1,4-phenylene diisothiocyanate (PDITC) linker. The assembly processes of the immunosensor had been monitored with cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques using Fe(CN)(6)(3-/4-) solution as redox probe. The impedance changes upon binding of MDM2 protein to the sensor surface was utilized for the detection of MDM2. The increase in relative electron-transfer resistance (ΔR/R(0)%) values was linearly proportional to the concentration of tumor marker MDM2 in the wide dynamic range of 1pg/ml-1μg/ml. The limit of detection was 0.29pg/ml in phosphate buffer saline (PBS) and 1.3pg/ml in mouse brain tissue homogenate, respectively. The immunosensor showed a good performance in comparison with ELISA for the analysis of the MDM2 in the cancerous mouse brain tissue homogenates. Moreover, the immunosensor had a good selectivity against epidermal growth factor receptor (EGFR) protein, long-storage stability and reproducibility. It might be become a promising assay for clinical diagnosis and early detection of tumors.
INRS Énergie, Matériaux et Télécommunications, Varennes, QC, Canada.
Reda
R
Elshafey
Chaker
C
Tlili
Abedelnasser
A
Abulrob
Ana C
AC
Tavares
Mohammed
M
Zourob
D000818:Animals; D055910:Antibodies, Immobilized / Q000276:immunology; D015374:Biosensing Techniques / Q000379:methods; D001921:Brain / Q000473:pathology*; D001923:Brain Chemistry; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology; D003543:Cysteamine / Q000737:chemistry; D058266:Dielectric Spectroscopy / Q000379:methods*; D004566:Electrodes; D006801:Humans; D007118:Immunoassay / Q000379:methods; D057230:Limit of Detection; D051379:Mice; D051736:Proto-Oncogene Proteins c-mdm2 / Q000032:analysis* / Q000276:immunology; D013861:Thiocyanates / Q000737:chemistry
D055910:Antibodies, Immobilized; D013861:Thiocyanates; D003543:Cysteamine; C032582:bitoscanate; D051736:Proto-Oncogene Proteins c-mdm2