title: A regenerating self-assembled gold nanoparticle-containing electrochemical impedance sensor.
abstract: We report on the development of an electrochemical reductive desorption protocol for repeated regeneration of gold electrodes modified with multi-layers of self-assembled surfaces for use in electrochemical sensing. The gold electrodes were first modified with 1,6-hexanedithiol to which gold nanoparticles were attached in a subsequent modification step. Attachment of thiolated single-stranded nucleic acid oligomers to the gold nanoparticles completed the electrochemical sensor. 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. The self-assembled sensor showed a wide dynamic range (0.1-100 nM), a low detection limit (20 pM) and high reproducibility (4.4% RSD) for complementary nucleic acid target molecules, along with reusability. On a single gold electrode, the complete sensor-target structure could be assembled and disassembled at least four times with 90% of its original signal intact.
authors: Department of Chemistry, University of Alberta, Edmonton, AB, Canada T6G 2G2.
authors: Amr M
authors: AM
authors: Mahmoud
authors: Defence Research & Development Canada-Suffield Research Centre, Medicine Hat, AB, Canada T1A 8K6.
authors: Thompson
authors: T
authors: Tang
authors: Department of Chemistry, University of Alberta, Edmonton, AB, Canada T6G 2G2; National Institute for Nanotechnology, National Research Council Canada, 11421 Saskatchewan Drive, Edmonton, AB, Canada T6G 2M9.
authors: D Jed
authors: DJ
authors: Harrison
authors: Defence Research & Development Canada-Suffield Research Centre, Medicine Hat, AB, Canada T1A 8K6.
authors: William E
authors: WE
authors: Lee
authors: National Institute for Nanotechnology, National Research Council Canada, 11421 Saskatchewan Drive, Edmonton, AB, Canada T6G 2M9. Electronic address: abebaw.jemere@nrc-cnrc.gc.ca.
authors: Abebaw B
authors: AB
authors: Jemere
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques / Q000295:instrumentation; D004247:DNA / Q000032:analysis*; D015342:DNA Probes / Q000737:chemistry; D058266:Dielectric Spectroscopy; D017097:Electric Impedance; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D015203:Reproducibility of Results; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D015342:DNA Probes; D013438:Sulfhydryl Compounds; D006046:Gold; D004247:DNA; C501433:1,6-hexanedithiol
keywords: Cyclic voltammetry; Electrochemical impedance spectroscopy; Electrode regeneration; Gold nanoparticles modified electrodes; Self-assembly