A high-performance VEGF aptamer functionalized polypyrrole nanotube biosensor

Biomaterials. 2010 Jun;31(17):4740-7. doi: 10.1016/j.biomaterials.2010.02.040. Epub 2010 Mar 12.


In this study, we examined the in vitro electrochemical detection of Vascular Endothelial Growth Factor (VEGF) as cancer biomarker using p-type field-effect transistor (FET) biosensor. We demonstrated the high-performance FET sensor, which could detect ca. 400 fM of VEGF concentration, based on anti-VEGF RNA aptamer conjugated carboxylated polypyrrole nanotubes (CPNTs). The CPNTs used as high-performance transducers of this FET system were successfully fabricated by cylindrical micelle templates in a water-in-oil emulsion system. The functional carboxyl group (-COOH) was effectively incorporated into the polymer backbone during the polymerization by using pyrrole-3-carboxylic acid (P3CA) as a co-monomer. Two types of CPNTs (CPNT1: ca. 200 nm in diameter, CPNT2: ca. 120 nm in diameter) demonstrated the excellent conductivity performance in this FET system. Based on CPNTs conjugated with anti-VEGF RNA aptamer (CPNTs-aptamer), VEGF (target molecule) acts as the gate dielectrics of p-type FET sensor and specifically interacts with anti-VEGF aptamer attached to CPNT surfaces. Importantly, the VEGF detection limit of the FET sensor based on CPNT2-aptamer was found to be near 400 fM in real-time. Moreover, the CPNTs-aptamer FET sensors can be repeatedly used for various concentrations of the target molecule (VEGFs) through the washing and rinsing processes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aptamers, Nucleotide / chemistry*
  • Biosensing Techniques / methods*
  • Models, Theoretical
  • Nanotubes / chemistry*
  • Polymers / chemistry*
  • Pyrroles / chemistry*
  • Vascular Endothelial Growth Factor A / analysis*
  • Vascular Endothelial Growth Factor A / genetics*


  • Aptamers, Nucleotide
  • Polymers
  • Pyrroles
  • Vascular Endothelial Growth Factor A
  • polypyrrole