Abstract:
A green and rapid approach was applied in synthesizing water-soluble N-acetyl-Lcysteine
(NAC)-capped ZnSe quantum dots (QDs) in the aqueous phase via
microwave irradiation. The precursors used were relatively less toxic and did not
need pre-treatment prior to reaction. Using IR spectroscopy, NAC molecules
were revealed to be successfully mounted on the surface of core ZnSe QDs
making the nanoclusters water-soluble. Absorption and emission measurements
revealed that the size of the products increases as the duration of reflux
increases. The sharp excitonic feature of the absorption spectra was also
indicative of the narrow size distribution of the synthesized quantum dots. The
as-per synthesized NAC-capped ZnSe QD was determined to possess
photoluminescence quantum yield (PLQY) of up to 18% in reference to
Rhodamine 6G without post-treatments. Optimum %PLQY was revealed to occur
after 60 minutes of reflux. The method employed in synthesizing water-soluble
ZnSe quantum dots was proven to be fast and less toxic and showed to improve
the optical properties of quantum dots with respect to conventional heating.