Molecularly imprinted solid‐phase extraction combined with molecularly imprinted polymer‐sensor: a diagnostic tool applicable to creatine deficiency syndrome

Abstract

Abstract Primary creatine deficiency syndromes (CDS) are a new group of disorders caused by guanidinoacetate methyltransferase (GAMT) deficiency, which affects endogenous creatine biosynthesis with depletion of body creatine. A deficiency in creatine can be corrected by treatment with oral creatine supplementation and this necessitates a simple and sensitive screening method for early detection of creatine in dilute physiologic fluids. In this work an artificial receptor, molecularly imprinted polymer (MIP), for creatine was used both as a material for solid‐phase extraction (SPE) and as a sensing element in a voltammetric sensor. Using the combination of molecularly imprinted solid‐phase extraction (MISPE) with a complementary MIP sensor, the minimum detectable amount was found to be 0.0015 ng mL −1 (RSD = 1.3%, S/N = 3). The MISPE‐MIP sensor combination provided up to 60‐fold preconcentration, which was more than sufficient for achieving the required quantification limit 50 ng mL −1 (or 0.0025 ng mL −1 after 2 × 10 4 ‐fold dilution) for creatine in human blood serum. Copyright © 2007 John Wiley & Sons, Ltd.