Toward single-DNA electrochemical biosensing by graphene nanowalls

Akhavan, O ; Sharif University of Technology | 2012

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  1. Type of Document: Article
  2. DOI: 10.1021/nn300261t
  3. Publisher: 2012
  4. Abstract:
  5. Graphene oxide nanowalls with extremely sharp edges and preferred vertical orientation were deposited on a graphite electrode by using electrophoretic deposition in an Mg 2+-GO electrolyte. Using differential pulse voltammetry (DPV), reduced graphene nanowalls (RGNWs) were applied for the first time, in developing an ultra-high-resolution electrochemical biosensor for detection of the four bases of DNA (G, A, T, and C) by monitoring the oxidation signals of the individual nucleotide bases. The extremely enhanced electrochemical reactivity of the four free bases of DNA, single-stranded DNA, and double-stranded DNA (dsDNA) at the surface of the RGNW electrode was compared to electrochemical performances of reduced graphene nanosheet (RGNS), graphite, and glassy carbon electrodes. By increasing the number of DPVs up to 100 scans, the RGNW electrode exhibited an excellent stability with only 15% variation in the oxidation signals, while for the RGNS electrode no detectable signals relating to T and C of 0.1 μM dsDNA were observed. The linear dynamic detection range of the RGNW electrode for dsDNA was checked in the wide range of 0.1 fM to 10 mM, while for the RGNS electrode, it was from 2.0 pM to <10 mM. The lower limits of dsDNA detection of the RGNW and RGNS electrodes were estimated as 9.4 zM (∼5 dsDNA/mL) and 5.4 fM, respectively. The RGNWs were efficient in label-free detection of single nucleotide polymorphisms of 20 zM oligonucleotides (∼10 DNA/mL) having a specific sequence. Therefore, the RGNWs can effectively contribute to the development of ultra-high-sensitive electrochemical biosensors with single-DNA resolutions
  6. Keywords:
  7. Graphene ; Detectable signal ; Detection limits ; Differential pulse voltammetry ; Double-stranded DNA (ds-DNA) ; Electrochemical biosensing ; Electrochemical biosensor ; Electrochemical performance ; Electrochemical reactivity ; Electrophoretic depositions ; Free basis ; Glassy carbon electrodes ; Graphene oxides ; Label-free detection ; Linear dynamics ; Lower limits ; Nanowalls ; Nucleotide basis ; Oxidation signal ; Sharp edges ; Single-stranded DNA ; Specific sequences ; Biosensors ; Deposition ; DNA ; Electrophoresis ; Glass membrane electrodes ; Graphite electrodes ; Oligonucleotides ; Signal detection ; Voltammetry ; Chemical detection ; Graphite ; Nanomaterial ; Chemistry ; Electric conductivity ; Genetic procedures ; Genetics ; Instrumentation ; Methodology ; Single nucleotide polymorphism ; Biosensing Techniques ; Electrochemistry ; Electrodes ; Nanostructures ; Oxides ; Polymorphism, Single Nucleotide
  8. Source: ACS Nano ; Volume 6, Issue 4 , March , 2012 , Pages 2904-2916 ; 19360851 (ISSN)
  9. URL: http://pubs.acs.org/doi/abs/10.1021/nn300261t