Tunable nanogap devices for ultra-sensitive electrochemical impedance biosensing.
Anal Chim Acta
; 905: 58-65, 2016 Jan 28.
Article
em En
| MEDLINE
| ID: mdl-26755137
ABSTRACT
A wealth of research has been available discussing nanogap devices for detecting very small quantities of biomolecules by observing their electrical behavior generally performed in dry conditions. We report that a gold nanogapped electrode with tunable gap length for ultra-sensitive detection of streptavidin based on electrochemical impedance technique. The gold nanogap is fabricated using simple monolayer film deposition and in-situ growth of gold nanoparticles in a traditional interdigitated array (IDA) microelectrode. The electrochemical impedance biosensor with a 25-nm nanogap is found to be ultra-sensitive to the specific binding of streptavidin to biotin. The binding of the streptavidin hinder the electron transfer between two electrodes, resulting in a large increase in electron-transfer resistance (Ret) for operating the impedance. A linear relation between the relative Ret and the logarithmic value of streptavidin concentration is observed in the concentration range from 1 pM (picomolar) to 100 nM (nanomolar). The lowest detectable concentration actually measured reaches 1 pM. We believe that such an electrochemical impedance nanogap biosensor provides a useful approach towards biomolecular detection that could be extended to a number of other systems.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Técnicas Biossensoriais
/
Impedância Elétrica
/
Nanotecnologia
Tipo de estudo:
Diagnostic_studies
Idioma:
En
Revista:
Anal Chim Acta
Ano de publicação:
2016
Tipo de documento:
Article