A reagentless amperometric carbon paste based sensor for NADH

Abstract

Carbon paste electrodes, based on zirconium phosphate with immobilized N-methylphenazonium or Nile blue, were prepared. The electrodes show anodic current response to NADH at an operating potential ranging from - 0.05 to 0.30 V (vs. SCE). The sensitivity of electrodes to NADH was shown to increase with increasing operation potential. It was shown that the concentration dependences for electrodes, obtained at different operating potentials. follow Michaelis-Menten scheme. confirming an electrodcatalytic mechanism for electrooxidation of NADH with a precursor complex formation. The detection limit for NADH was found to be ca. 2 mu M for both types of sensors.12319419