Immobilization of xanthine oxidase and its use in the quantitation of hypoxanthine in fish muscle tissue extracts using a flow injection method

Mediated xanthine oxidase potentiometric biosensors for hypoxanthine based on ferrocene carboxylic acid modified electrode

“…The concentrations of hypoxanthine found in the three different fish muscles ranged from 2.1 to 8.7 lmol/g. The results are within the range of values previously reported for common fish fillet by lmole/g) (Balladin et al (1997)) and lmol/g) after day 1 (Zen, Lai, Yang, & Kumar, 2002). lmol/g) on day 1 (Carsol, Volpe, & Mascini, 1997).…”

“…The limit of detection compares favourably with that of 3.6 lM reported by Mulchandani et al (1989aMulchandani et al ( , 1989b for Hx using xanthine oxidase immobilised in nylon. This is approximately 16-fold lower than that of the oxygen-based biosensor developed by Watanabe, Tamada, and Hamada-Sato (2005) and 100-fold lower than that developed by Balladin et al (1997). This linear range is suitable for the determination of Hx in biological and clinical samples.…”

“…It appears that the thicker the film produced the more Fe(CN) 6 4À is incorporated into the conductive polypyrrole film and the higher the current or potential change produced. However, the response time to reach a steady state is longer for thicker films and thus, the selection of an optimal thickness of polypyrrole film is necessary (Balladin et al, 1997). The effect of PPy layer thickness for film prepared in the presence of XOD on potentiometric response was thus examined.…”

“…Several extraction solutions, including perchloric acid (Balladin, Narinesingh, Stoute, & Ngo, 1997;Valle, Malle, & Bouquelet, 1998), water (Nakatani et al, 2005; and trichloroacetic acid (TCA) and phosphate buffer (Agüí, Manso, Yáñez-Sedeño, & Pingarrón, 2006) have been used to prepare fish samples for Hx analysis. Distilled water was used in this study.…”

“…Such agreement suggests that the PPy-XOD-Fc electrode is useful for reliable, simple and economical detection of Hx. It has been showed that there is no significant difference between HPLC and xanthine oxidase biosensor values (Balladin et al, 1997).…”