Highly
Sensitive and Selective Detection of Dopamine
Using One-Pot Synthesized Highly Photoluminescent Silicon Nanoparticles
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Abstract
A simple and highly efficient method
for dopamine (DA) detection
using water-soluble silicon nanoparticles (SiNPs) was reported. The
SiNPs with a high quantum yield of 23.6% were synthesized by using
a one-pot microwave-assisted method. The fluorescence quenching capability
of a variety of molecules on the synthesized SiNPs has been tested;
only DA molecules were found to be able to quench the fluorescence
of these SiNPs effectively. Therefore, such a quenching effect can
be used to selectively detect DA. All other molecules tested have
little interference with the dopamine detection, including ascorbic
acid, which commonly exists in cells and can possibly affect the dopamine
detection. The ratio of the fluorescence intensity difference between
the quenched and unquenched cases versus the fluorescence intensity
without quenching (Δ<i>I</i>/<i>I</i>) was
observed to be linearly proportional to the DA analyte concentration
in the range from 0.005 to 10.0 μM, with a detection limit of
0.3 nM (<i>S</i>/<i>N</i> = 3). To the best of
our knowledge, this is the lowest limit for DA detection reported
so far. The mechanism of fluorescence quenching is attributed to the
energy transfer from the SiNPs to the oxidized dopamine molecules
through Förster resonance energy transfer. The reported method
of SiNP synthesis is very simple and cheap, making the above sensitive
and selective DA detection approach using SiNPs practical for many
applications