National Research Council of Canada. National Institute for Nanotechnology
Cyclic voltammetry; Desorption; Electrochemical electrodes; Fiber optic sensors; Gold; Metal nanoparticles; Nanoparticles; Self assembled monolayers; Spectroscopy; Viruses; X ray photoelectron spectroscopy; 11-mercaptoundecanoic acid; Adenovirus; Covalent immobilization; Electrochemical impedance; Linear dynamic ranges; Modified electrodes; Reductive desorption; Self-assembled layers; Electrochemical impedance spectroscopy; gold nanoparticle; undecanoic acid; virus antibody; chemical modification; chemical reaction; concentration (parameters); cyclic potentiometry; electrochemical impedance spectroscopy; electrode; immobilization; immunosensor; limit of detection; virus detection; Human adenovirus type 5
We report on the development of a regenerable sensitive immunosensor based on electrochemical impedance spectroscopy for the detection of type 5 adenovirus. The multi-layered immunosensor fabrication involved successive modification steps on gold electrodes: (i) modification with self-assembled layer of 1,6-hexanedithiol to which gold nanoparticles were attached via the distal thiol groups, (ii) formation of self-assembled monolayer of 11-mercaptoundecanoic acid onto the gold nanoparticles, (iii) covalent immobilization of monoclonal anti-adenovirus 5 antibody, with EDC/NHS coupling reaction on the nanoparticles, completing the immunosensor. The immunosensor displayed a very good detection limit of 30 virus particles/ml and a wide linear dynamic range of 105. An electrochemical reductive desorption technique was employed to completely desorb the components of the immunosensor surface, then re-assemble the sensing layer and reuse the sensor. On a single electrode, the multi-layered immunosensor could be assembled and disassembled at least 30 times with 87% of the original signal intact. The changes of electrode behavior after each assembly and desorption processes were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy techniques.
Biosensors and Bioelectronics68 (16 December 2014): 129–134.