Electrochemical immunosensor for label free epidermal growth factor receptor (EGFR) detection

This paper presents an electrochemical immune sensor for label free detection of epidermal growth factor receptor (EGFR) by immobilizing anti-EGFR antibody (Anti-EGFRab) on dithiobissuccinimidyl propionate (DTSP) self-assembled monolayer (SAM) on gold (Au) electrode. Electrochemical studies show that increased surface concentration of redox moieties onto Anti-EGFRab/DTSP immuno-electrode leads to high electron transport and improved sensing performance. The antigen–antibody complex demonstrates a high association constant (5×1012 L/mol) that results in high affinity of Anti-EGFRab to EGFR, confirming that the DTSP–SAM provides a conducive environment for anti-EGFR immobilization. The electrochemical response of EA/Anti-EGFRab/DTSP/Au electrode as a function of EGFR concentrations exhibits a linear range from 1 pg/mL to 100 ng/mL, a detection limit of 1 pg/mL at a sensitivity of 2.02 μA M−1at a regression coefficient of 0.99.

► We present an electrochemical sensor for epidermal growth factor receptor detection.
► Self-assembled monolayer is used as immobilizing matrix.
► Sensor range: from 1 pg/mL to 100 ng/mL, detection limit: 1 pg/mL, sensitivity: 2.02 μA M−1.