A three-enzyme microelectrode sensor for detecting purine release from central nervous system

Biosens Bioelectron. 2003 Jan;18(1):43-52. doi: 10.1016/s0956-5663(02)00106-9.


As the purines, in particular adenosine, are important signaling agents in the nervous system we have devised a new biosensor for directly measuring their production in real time during physiological activity. Our amperometric adenosine biosensor is made by entrapping 3 enzymes (xanthine oxidase, purine nucleoside phosphorylase and adenosine deaminase) in a composite lactobionamide and amphiphillic polypyrrole matrix around a Pt microelectrode. The resulting sensors are small (25-100 microm diameter), fast responding (10-90% rise time, 2+/-0.23 s), sensitive (100-222 mA M(-1) cm(-2)) and stable (100% activity after 5 days). The sensor was used in vivo to demonstrate the spatial localization of release of adenosine from Xenopus embryo spinal cord during fictive swimming.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biosensing Techniques / instrumentation*
  • Central Nervous System / metabolism
  • Electrodes
  • Purines / analysis*
  • Purines / metabolism
  • Xenopus


  • Purines