Anal. Chem. 2008, 80, 7910–7917
Electrochemical Creatinine Biosensors Umesh Lad, Santosh Khokhar, and Girish M. Kale University of Leeds (U.K.) To measure creatinine, electrochemical techniques have been coupled with a range of biological recognition elements in a variety of sensor configurations. (To listen to a podcast about this feature, please go to the Analytical Chemistry website at pubs.acs.org/ac. The measurement of creatinine levels in human blood or urine is clinically essential because the levels partially reflect the state of renal and muscle function. Creatinine is naturally produced by the body and is filtered from the bloodstream by the kidneys in relatively constant amounts every day. The normal physiological concentration is 40-150 µM, but it can exceed 1000 µM in certain pathological conditions. Blood levels >150 µM indicate the need to perform tests such as creatinine clearance. Values >500 µM indicate severe renal impairment, ultimately leading to dialysis or transplantation;1 levels