Green and Rapid Synthesis of N-acetyl-L-cysteinecapped ZnSe Quantum Dots in the Aqueous Phase via Microwave Irradiation.

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.