The necessity of disposable biosensors for simple, rapid and inexpensive
analysis in fields such as clinical, environmental or industrial has been highlighted
over the past decade. In this way, screen-printed electrodes (SPEs) have been shown
as inexpensive and reproducible devices for mass production of miniaturized
biosensors [1-4]. These transducers, building by sequential layer deposition on the
surface of ceramic or plastic substrates and curing steps, have been conventionally
linked to the sensing element by adsorption, cross-linking, electropolymerization or
covalent bonding. Bioelements are commonly immobilized after the printing and
firing processes, because of the high temperatures reached during the curing step [5].
The immobilization procedure requires maintaining the initial properties of the
enzyme intact. Thus, successful developments of biosensors largely rely on the cost
and stability of the sensing elements [3].
Even if the above-mentioned immobilization procedures are efficient, they
imply additional steps after fabrication of the screen-printed carbon electrodes
(SPCEs), which extends the whole biosensor manufacturing. Screen-printing
techniques also offer another attractive immobilization procedure consisting of
printing the biological material. Enzymes, which are proteins able to catalyse specific
chemical reactions in vivo, are by far the most commonly employed bioelements [1].
Enzymes can be integrated into the ink to form the sensing paste, which can be
screen-printed resulting in biosensors fabricated by only one technology [6-8].
Undoubtedly, this immobilization procedure, which is known as automated
immobilization, is particularly interesting for mass production of disposable
biosensors.
This work presents a simple way for preparing SPCEs modified with
Horseradish peroxidase (HRP) for the determination of Levetiracetam (LEV). This
second-generation antiepileptic drug (AEDs) has been previously determined using a
SPCE-biosensor based on the immobilization of Horseradish peroxidase (HRP) by
pyrrole electropolymerization [9] and covalent bonding [10] The screen-printing of
HRP-containing ink (SPCHRPEs) offers a higher rapidity and simplicity in the
manufacturing process of biosensors for LEV determination.
