ECL has become an important and valuable detection method in
analytical chemistry in recent years. ECL is a means of converting
electrical energy into radiative energy. It involves the production
of reactive intermediates from stable precursors at the surface of
an electrode. These intermediates then react under a variety of
conditions to form excited states that emit light [15]. ECL allows
the detection of analytes at low concentrations over a wide linear
range. This is partly due to the electrochemical excitation during
ECL reactions. The absence of an excitation light source produces
a low background signal. This allows a highly sensitive detection
without expensive instrumentation. The electrochemical initiation
of the ECL reaction also introduces great temporal control over the
reaction [16]. The majority of analytical applications of ECL now
appearing in the literature are concerned with the indirect ECL of
Ru(bpy)3
2+ [17,18] and luminol [19,20]. In contrast with the indirect
ECL, direct ECL does not need luminescence additives, such as
Ru(bpy)3
2+ or luminol. However, organic molecules having struc-tural character capable of direct ECL have been explored relatively
infrequently when compared to the indirect ECL of Ru(bpy)3
2+
and luminol. In our previous work, a sensitive direct ECL method
has been developed and used to post-column determination of
ofloxacin in human serum [21].
In our presentwork, a newECL methodwas developed to determinate
naproxen. It was based on the ECL of naproxen in basic
NaNO3 solution. Factors affected the ECL emission of naproxenwere
investigated and a simple mechanism was proposed. Under the
optimal conditions, the method has been used for determination
of naproxen in human urine.