Determination of Creatine and Creatinine Using a Diamond Paste Based Electrode

Abstract A diamond paste based electrode is proposed for the simultaneous assay of creatine and creatinine. Natural diamond is used for the construction of the electrode. The electrode can be reliably used for creatine and creatinine assay in pharmaceutical formulations and serum samples. The potentials used for the assay of creatine and creatinine were 580 mV and 500 mV vs. Ag/AgCl electrode, respectively. The linear concentration ranges for the proposed electrode were in the ranges of 1–500 pmol/L (creatine) and 0.01–100 nmol/L (creatinine) with low limits of detection and RSD values better than 0.21% (n = 10).