Development of a sandwich format, amperometric screen-printed uric acid biosensor for urine analysis

• Published in: Analytical biochemistry Vol. 428; no. 1; pp. 39 - 43
• Main Authors: Kanyong, P., Pemberton, R.M., Jackson, S.K., Hart, J.P.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.09.2012
• Subjects: Biosensing Techniques - instrumentation; Biosensing Techniques - methods; biosensors; Buffers; Calibration; carbon; Cellulose acetate; Chronoamperometry; cobalt; Cyclic voltammetry; detection limit; Electrochemistry - instrumentation; Electrochemistry - methods; electrodes; Humans; Hydrogen peroxide; ionic strength; temperature; Uric acid; Uric Acid - urine; Uricase; urinalysis; Urinalysis - instrumentation; Urinalysis - methods; urine; Cyclic voltammetry; Hydrogen peroxide; Uric acid; Uricase; Cellulose acetate; Chronoamperometry
• ISSN: 0003-2697; 1096-0309; 1096-0309
• DOI: 10.1016/j.ab.2012.05.027

A screen-printed carbon electrode (SPCE) incorporating the electrocatalyst cobalt phthalocyanine (CoPC), fabricated using a water-based ink formulation, has been investigated as the base transducer for a uric acid biosensor. A sandwich biosensor was fabricated by first depositing cellulose acetate (CA) onto this transducer (CoPC–SPCE), followed by uricase (UOX) and finally a polycarbonate (PC) membrane; this device is designated PC–UOX–CA–CoPC–SPCE. This biosensor was used in conjunction with chronoamperometry to optimize the conditions for the analysis of urine: temperature, 35°C; buffer, pH 9.2; ionic strength, 50mM; uricase, 0.6U; incubation time, 180s. The proposed biosensor was applied to urine from a healthy subject. The precision determined on unspiked urine (n=6) was 5.82%. Urine was fortified with 0.225mM UA, and the resulting precision and recovery were 4.21 and 97.3%, respectively. The linear working range of the biosensor was found to be 0.015 to 0.25mM (the former represents the detection limit), and the sensitivity was calculated to be 2.10μA/mM.