Electrocatalytic miRNA detection using cobalt porphyrin-modified reduced graphene oxide

Sensors (Basel). 2014 Jun 6;14(6):9984-94. doi: 10.3390/s140609984.


Metalated porphyrins have been described to bind nucleic acids. Additionally, cobalt porphyrins present catalytic properties towards oxygen reduction. In this work, a carboxylic acid-functionalized cobalt porphyrin was physisorbed on reduced graphene oxide, then immobilized on glassy carbon electrodes. The carboxylic groups were used to covalently graft amino-terminated oligonucleotide probes which are complementary to a short microRNA target. It was shown that the catalytic oxygen electroreduction on cobalt porphyrin increases upon hybridization of miRNA strand ("signal-on" response). Current changes are amplified compared to non-catalytic amperometric system. Apart from oxygen, no added reagent is necessary. A limit of detection in the sub-nanomolar range was reached. This approach has never been described in the literature.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cobalt / chemistry*
  • Electrochemical Techniques / methods*
  • Electrodes
  • Graphite / chemistry*
  • MicroRNAs / analysis*
  • MicroRNAs / chemistry
  • Molecular Probe Techniques*
  • Oxidation-Reduction
  • Oxides / chemistry
  • Porphyrins / chemistry*


  • MicroRNAs
  • Oxides
  • Porphyrins
  • Cobalt
  • Graphite