Simultaneous determination of adenosine and inosine using single-wall carbon nanotubes modified pyrolytic graphite electrode

Voltammetric determination of adenosine and inosine has been carried out at single-wall carbon nanotubes (SWNTs) modified pyrolytic graphite electrode (PGE) at pH 7.2 using Osteryoung square wave voltammetry (OSWV). The modified electrode exhibits remarkable electrocatalytic properties towards adenosine and inosine oxidation with a peak potential of similar to 1229 mV and 1348 mV, respectively. Linear calibration curves are obtained over the concentration range 0.5 mu M to 1.0 mM in adenosine and 10 mu M to 1.0 mM in inosine with sensitivity of 1.0 mu A mu M-1 and 1.9 mu A mu M-1 for adenosine and mosine respectively. The limit of detection for adenosine and inosine was found to be 0.51 x 10(-7) M and 2.04 x 10(-7) M, respectively. The proposed method was also used to estimate these compounds in human blood plasma and urine samples and the method was validated using HPLC. (C) 2008 Elsevier B.V. All rights reserved.