Fabrication of electrochemical DNA sensors on gold-modified recessed platinum nanoelectrodes

S. Ehsan Salamifar, Rebecca Y. Lai

Research output: Contribution to journalArticle

33 Scopus citations

Abstract

We report the use of gold-modified recessed platinum (Pt) nanoelectrodes in the fabrication of linear and stem-loop probe-based electrochemical DNA (E-DNA) sensors. Pt nanoelectrodes with a radius less than 10 nm were reproducibly fabricated using an optimized laser pulling technique. Prior to sensor fabrication, the nanoelectrode was electrochemically etched to create a recessed nanopore, followed by electrodeposition of gold into the nanopore using either cyclic voltammetry or constant potential amperometry. Both techniques enabled controlled deposition of gold into the nanopores, resulting in a nanostructured gold electrode with a well-defined surface area. In addition, we systematically determined the optimal experimental condition for DNA probe immobilization and target interrogation. The electron transfer rate constants of methylene blue, as determined using alternating current voltammetry, were found to be much higher than those obtained from E-DNA sensors fabricated on conventional macroscale electrodes. While this unique phenomenon requires further investigation, our results clearly show that these gold-modified nanoelectrodes can be used as substrates for this class of electrochemical biosensors.

Original languageEnglish (US)
Pages (from-to)2849-2852
Number of pages4
JournalAnalytical chemistry
Volume86
Issue number6
DOIs
StatePublished - 2014

ASJC Scopus subject areas

  • Analytical Chemistry

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