title: Development of an amperometric screen-printed galactose biosensor for serum analysis.
abstract: The development of a disposable amperometric biosensor for the measurement of circulating galactose in serum is described. The biosensor comprises a screen-printed carbon electrode (SPCE), incorporating the electrocatalyst cobalt phthalocyanine (CoPC), which is covered by a permselective cellulose acetate (CA) membrane and a layer of immobilized galactose oxidase (GALOX). The optimal response of the biosensor, designated as GALOX-CA-CoPC-SPCE, was obtained by systematically examining the effects of enzyme loading, temperature, pH, and buffer strength. The optimal performance of the biosensor occurred with 2U of GALOX, at 35°C, using 50mM phosphate buffer solution (pH 7.0). The sensitivity was 7.00μAmM(-1)cm(-2) and the linear range from 0.1 to 25mM with a calculated limit of detection (LOD) of 0.02mM; this concentration range and LOD are appropriate to diagnose galactosemia, i.e., concentrations >1.1mM in infants. When the biosensor was used in conjunction with amperometry in stirred solution for the analysis of serum, the precision values obtained on unspiked (endogenous level of 0.153mM) and spiked serum (1mM added) (n=6) were 1.10% and 0.11%, respectively, with a calculated recovery of 99.9%.
authors: Centre for Research in Biosciences, Faculty of Health and Life Sciences, University of the West of England, Frenchay Campus, Bristol, UK.
authors: Prosper
authors: P
authors: Kanyong
authors: Roy M
authors: RM
authors: Pemberton
authors: Simon K
authors: SK
authors: Jackson
authors: John P
authors: JP
authors: Hart
mesh_terms: D055162:Biocatalysis; D015374:Biosensing Techniques; D002244:Carbon / Q000737:chemistry; D055664:Electrochemical Techniques; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000378:metabolism; D005690:Galactose / Q000097:blood*; D005692:Galactose Oxidase / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007211:Indoles / Q000737:chemistry; D007223:Infant; D009942:Organometallic Compounds / Q000737:chemistry; D013696:Temperature
chemical_list: D004800:Enzymes, Immobilized; D007211:Indoles; D009942:Organometallic Compounds; C063633:cobalt phthalocyanine; D002244:Carbon; D005692:Galactose Oxidase; D005690:Galactose