ABSTRACT
The highly sensitive and selective potentiometric biosensor for creatinine determination has been developed by us earlier. In it, pH-sensitive field effect transistors were used as transducer and immobilized creatinine deiminase (EC 3.5.4.21)--as a biosensitive element. In the work presented, we optimized this biosensor for creatinine analysis in real samples of dialysate in patients with renal failure. The optimized version of biosensor was applied for on-line monitoring of the level of creatinine in the patient's dialysate fluid in the course of dialysis session. High correlation between the biosensor analysis and traditional Jaffe method was demonstrated.
Subject(s)
Biosensing Techniques/methods , Creatinine/analysis , Renal Dialysis , Biosensing Techniques/statistics & numerical data , Body Fluids/chemistry , Humans , Kidney Failure, Chronic/metabolism , Kidney Failure, Chronic/therapy , Sensitivity and SpecificityABSTRACT
A differential pair of planar thin-film interdigitated electrodes, deposited on a ceramic pad, was used as a conductometric transducer. The three-enzyme system (invertase, mutarotase, glucose oxidase), immobilized on the transducer surface, was used as a bioselective element. The ratio between enzymes in the membrane was found experimentally considering the highest biosensor sensitivity to substrate (sucrose) and heavy metal ions. Optimal concentration of sucrose for inhibitory analysis was 1.25 mM and incubation time in the investigated solution amounted to 10-20 min. The developed biosensor demonstrated the best sensitivity toward ions Hg(2+) and Ag(+). A principal possibility of the biosensor reactivation either by EDTA solution after inhibition with silver ions or by cysteine solution after inhibition with mercury ions was shown.
