Analytical and Bioanalytical Chemistry

, Volume 402, Issue 1, pp 413–421 | Cite as

Probe accessibility effects on the performance of electrochemical biosensors employing DNA monolayers

  • Vanessa Biagiotti
  • Alessandro Porchetta
  • Sara Desiderati
  • Kevin W. Plaxco
  • Giuseppe Palleschi
  • Francesco Ricci
Original Paper


Surface-confined DNA probes are increasingly used as recognition elements (or presentation scaffolds) for detection of proteins, enzymes, and other macromolecules. Here we demonstrate that the density of the DNA probe monolayer on the gold electrode is a crucial determinant of the final signalling of such devices. We do so using redox modified single-stranded and double-stranded DNA probes attached to the surface of a gold electrode and measuring the rate of digestion in the presence of a non-specific nuclease enzyme. We demonstrate that accessibility of DNA probes for binding to their macromolecular target is, as expected, improved at lower probe densities. However, with double-stranded DNA probes, even at the lowest densities investigated, a significant fraction of the immobilized probe is inaccessible to nuclease digestion. These results stress the importance of the accessibility issue and of probe density effects when DNA-based sensors are used for detection of macromolecular targets.


Here we demonstrate that the density of the DNA probe monolayer is a crucial determinant of the final signalling of DNA-bases sensors used for the detection of proteins, enzymes, and other macromolecules.


Density DNA sensor SAM Protein Electrochemical 



The authors acknowledge members of our research groups for helpful discussions and comments on the manuscript. This work was supported by the Italian Ministry of University and Research (MIUR) through the project FIRB “Futuro in Ricerca”.


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Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Vanessa Biagiotti
    • 1
  • Alessandro Porchetta
    • 1
  • Sara Desiderati
    • 1
  • Kevin W. Plaxco
    • 3
  • Giuseppe Palleschi
    • 1
    • 2
  • Francesco Ricci
    • 1
    • 2
  1. 1.Dipartimento di Scienze e Tecnologie ChimicheUniversity of RomeRomeItaly
  2. 2.Consorzio Interuniversitario Biostrutture e Biosistemi “INBB”RomeItaly
  3. 3.Department of Chemistry and BiochemistryUniversity of CaliforniaSanta BarbaraUSA

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