Graphite-epoxy composites as a new transducing material for electrochemical genosensing

Biosens Bioelectron. 2003 Dec 30;19(5):473-84. doi: 10.1016/s0956-5663(03)00222-7.

Abstract

The use of a rigid carbon-polymer composite material as an electrochemical transducer in hybridisation genosensors is reported. Graphite-epoxy composites (GEC) have an uneven surface where DNA can be adsorbed using a simple dry-adsorption procedure. Single-stranded-DNA binds strongly to GEC in a way that prevents the strands from self-associating, while permitting hybridisation with complementary DNA. Hybridisation has been detected through biotin-streptavidin interaction using a streptavidin conjugated to horseradish peroxidase. Non-specific adsorption onto GEC is almost non-existent even when the surface has not been treated by blocking reagents. The analytical signal obtained was higher when compared with other electrochemical genosensors. Results can be achieved in 150 min, and the detection limit is in the order of fmol. Additionally, surface regeneration is possible using a simple polishing procedure, allowing for multiple use. The new genosensor based on GEC fulfils the requirements desired for these devices: ease of preparation as dry-adsorption of DNA is very simple and easily automated, robustness, sensitivity, low cost of production, ease of miniaturisation and simple use and fast response. Additionally, it can be used for field measurements and can be produced as a genosensor kit. Also, this material can be implemented for screen-printing procedures for the mass production of genosensors. The utility of the genosensor based on GEC is also illustrated with the detection of a sequence related to novel determinant of beta-lactamase resistance in Staphylococcus aureus.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Adsorption
  • Coated Materials, Biocompatible / chemical synthesis
  • Coated Materials, Biocompatible / chemistry
  • DNA / analysis*
  • DNA / chemistry*
  • DNA Probes / chemical synthesis
  • DNA Probes / chemistry*
  • Electrochemistry / instrumentation*
  • Electrochemistry / methods
  • Epoxy Compounds / chemistry*
  • Graphite / chemistry*
  • Manufactured Materials / analysis
  • Microchemistry / instrumentation*
  • Microchemistry / methods
  • Nylons
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Transducers

Substances

  • Coated Materials, Biocompatible
  • DNA Probes
  • Epoxy Compounds
  • Nylons
  • Graphite
  • DNA