Antibody regeneration on degenerate Si electrodes for calibration and reuse of impedance biosensors
By Radhakrishnan, Rajeswaran; Suni, Ian Ivar
Published in Sensing and Bio-Sensing Research
2016
Abstract
Abstract Mild denaturing agents were studied for antibody regeneration atop degenerate (highly doped) Si and Au electrodes using comparable 11-carbon chain linker reagents onto which the mouse monoclonal antibody to peanut protein Ara h 1 is covalently immobilized. Of the reagents studied, only 200 mM {KSCN} is effective for antibody regeneration and detection of Ara h 1 atop Au electrodes, allowing 15 days of sensor usage after daily antibody unfolding and refolding, while 200 mM {KSCN} + 10 mM {HF} is effective atop degenerate Si electrodes, allowing 30 days of sensor usage. The addition of {HF} is required for antibody regeneration atop Si electrodes, as demonstrated by cyclic voltammetry in the presence of 5.0 mM K3Fe(CN)6/K4Fe(CN)6 at pH 7.3, where the oxidation/reduction peaks can be observed only in the presence of HF. The impedance spectrum for detection of Ara h 1 gradually degrades during these multi-day regeneration trials, but calibration experiments performed within one day illustrate that sensor electrodes can be calibrated on the day of use to within about 2%.