| Summary: | Advances in the life sciences are now closely linked
to the availability of new experimental tools that allow for
the manipulation of biomolecules and the study of biological
processes at the molecular level. In this context, we have
optimized a synthesis process to obtain glutathione‐capped
fluorescent CdS nanoparticles to specifically detect
Glutathione S‐Transferase (GST) ‐tagged proteins. Using our
method, based on five different heating steps, brightly
fluorescent and biocompatible CdS quantum dots of
different sizes can be obtained. QD optical behaviour has
been evaluated studying both absorbance and fluorescence.
For all the samples, the excitonic absorption onset clearly
shows a blue shift at 512nm in comparison with that of bulk
CdS, due to the quantum confinement effect. At increased
average sizes of the nanocrystal, the emission fluorescent
band shows a red shift, from 440nm to 540nm. Among
different QD solutions, we demonstrate an expansion of the
emission range up to ~100 nm, thus improving their features
as biomarkers. Moreover we show that optimized glutathionecapped
quantum dots can directly bind GST blotted onto
polyvinylidene difluoride (PVDF) membranes, and thus are
suitable for the direct detection of GST fusion proteins.
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