Amperometric
tyrosinase
based
biosensor
for
benzoic
acid
determination
with
the
use
of
a
flow-batch
monosegmented
sequential
injection
system
is
proposed.
The
functioning
of
the
biosensor
is
based
on
the
inhibition
effect
of
benzoic
acid
on
the
biocatalytic
activity
of
tyrosinase,
polyphenol
oxidase.
In
the
biosensor,
tyrosinase
is
entrapped
in
titania
gel
modified
with
multiwalled
carbon
nanotubes
(MWCNT)
and
Nafion.
The
procedure
of
optimization
of
experimental
conditions
affecting
the
biosensor
response,
as
well
as
its
analytical
characteristics
and
results
of
the
approach
verification
using
synthetic
samples
and
a
reference
material
are
presented.
The
developed
biosensor
exhibits
linear
range
up
to
2.46
M,
good
sensitivity
toward
benzoic
acid
(1.06
A
M
−
1
)
and
low
detection
limit
(0.03
M).
The
approach
has
been
applied
to
benzoic
acid
determination
in
a
real
beverage
sample
giving
the
result
consistent
with
that
obtained
using
the
HPLC
method.