title: Direct glucose determination in blood using a reagentless optical biosensor.
abstract: This paper demonstrates that glucose determination in blood can be done directly (without sample pretreatment) using a reagentless reversible biosensor based on the intrinsic spectroscopic properties of peroxidase (HRP). The biosensor, prepared by HRP and glucose oxidase entrapment in a polyacrylamide gel matrix, works in continuous mode, presents a linear response range from 1.5 x 10(-6) up to 5.5 x 10(-5)M and can be used for at least 750 measurements; in the best conditions (0.1 M pH 6 phosphate buffer, HRP and GOx amounts in the polymersation mixture for the sensor film preparation 0.0165 and 0.0010 g, respectively) the minimum samples rate is 30 h(-1). For glucose determination, blood is simply diluted in water (until haemolysis is completed) and fed into the sensor without a cleaning step between samples; the blood absorption is corrected in a simple way by working at a proper reference wavelength. The biosensor signals have been mathematically modeled in order to facilitate the design of sensors based on the same idea for other biochemical compounds.
authors.affiliation: ABG (Analytical Biosensors Group), INA (Instituto de Nanociencia de Aragón), Analytical Chemistry Department, Faculty of Sciences, University of Zaragoza, 50009 Zaragoza, Spain.
authors.forename: Vanesa
authors.initials: V
authors.lastname: Sanz
authors.forename: Susana
authors.initials: S
authors.lastname: de Marcos
authors.forename: Javier
authors.initials: J
authors.lastname: Galbán
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D001786:Blood Glucose / Q000032:analysis*; D006735:Horseradish Peroxidase / Q000737:chemistry; D008962:Models, Theoretical
chemical_list: D001786:Blood Glucose; D006735:Horseradish Peroxidase