Electrochemical detection of creatinine: exploiting copper(ii) complexes at Pt microelectrode arrays.

This work develops a rapid and highly sensitive electrochemical sensor for creatinine detection at platinum microelectrode arrays (Pt-MEA). Copper(ii) ions are introduced to form the electroactive creatinine complex, which is then detected at Pt-MEA through a direct reduction reaction. Electrochemical behaviors of the creatinine complex are also explored at Pt macrodisc and microdisc electrodes in comparison with Pt-MEA. At the Pt-MEA, the linear range, sensitivity, and limit of detection of creatinine are determined to be 0.00-5.00 mM, 5401 ± 99 A m -2 M -1 , and 0.059 mM (3S B /m), respectively. Notably, the Pt-MEA requires only 10 μL of sample and allows direct measurement of creatinine in synthetic urine with 97.39 ± 4.78% recovery.