Enzymeless creatinine estimation using poly(3,4-ethylenedioxythiophene) -β-cyclodextrin

A novel enzymeless biosensor has been constructed for the quantitative estimation of creatinine using β-cyclodextrin (βCD) incorporated poly-3,4-ethylenedioxythiophene (PEDOT) modified glassy carbon electrode (GCE). The PEDOT film with and without βCD was deposited on a GCE by electropolymerization of EDOT from an aqueous solution containing lithium perchlorate and βCD. Polymer films were characterized by UV–visible spectroscopy, cyclic voltammetry and scanning electron microscopy (SEM). The selective interactions of the βCD-incorporated PEDOT film with creatinine in neutral Tris buffer solutions were elucidated using electrochemical impedance analysis. Complex formation between βCD and creatinine was inferred from regular shifts in the electrode potential versus creatinine concentration. In the potentiometric evaluation, the biosensor electrode exhibited a fast response time (60 s), linear shift in the potential over a concentration range of 10−4–10−1 M with a lower detection limit of 5 × 10−5 M and good stability, retaining nearly 95% of the initial response after 1 month of shelf life. The results of the studies on the interferences from glucose, ascorbic acid, uric acid, urea and ammonium ions are also presented.