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JUAN PABLO HERVÁS-PÉREZ Y COLS. AN. R. ACAD. NAC. FARM.

la influencia de distintos factores, tales como grado de reticulación, pH y tempera-
tura en la respuesta del biosensor. Las condiciones óptimas se corresponden a un
grado de reticulación del 7%, 40º C y pH 7,0. El sistema de inmovilización propues-
to apenas modifica la actividad enzimática, pero parece proteger a la enzima au-
mentando el intervalo de temperatura en el que es activa.

Palabras clave: Emulsión concentrada.—Micropartículas.—Electrodo enzimá-
tico.—Galactosa oxidasa.

ABSTRACT

Amperometric biosensor based on polyacrylamide microgels
for galactose determination

Galactosemia is one of the natural errors of the metabolism more frequent, its
clinical representation in children not treated can be severe, sometimes mortal; its
diagnostic is relatively simple and its treatment is very easy and effective. Hence,
in last years new biosensors design for galactose determination based on galactose
oxidase has been proposed. The aim of this work consists of the immobilization of
galactose oxidase (GlOx) in polyacrylamide microparticles, using the concentrated
emulsion method, and their use as biological material of a new amperometric
biosensor for galactose determination. For preparing the galactose biosensors,
microparticles with galactose oxidase were deposited on the surface of a platinum
electrode and covered with a dialysis membrane. Microparticles were characterized
by a Galai Cis-1 particle analyzer system, scanning electron microscopy, X-rays
diffraction and differential scanning calorimetry. The presence of galactose oxidase
decreases the transition temperature (Tg) of the polyacrylamide microgels. The
influence of several experimental factors, such as crosslinking content, pH and
temperature, on the biosensor response was investigated. The optimal performance
of the biosensor takes place for a cross-linking of 7.0%, 40ºC and pH 7.0. The
proposed immobilization system almost does not modify the enzyme activity, but
seems to protect to the enzyme because an increase of the temperature range in
which the enzyme is active is observed.

Key words: Concentrated emulsion.—Microparticles.—Enzyme electrode.—
Galactose oxidase.

INTRODUCCIÓN

Los biosensores amperométricos son dispositivos analíticos que
presentan una gran aplicación en campos tales como la química
clínica, la industria farmacéutica, la industria alimentaria, estudios
medioambientales, etc. Su campo de aplicación está en expansión

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