Aqueous-phase synthesis of ultra-stable small CdSe nanoparticles.
Very stable and small CdSe nanoparticles (NPs) were synthesized from the aqueous solutions containing L-cysteine (Cys) at room temperature. The Cys-capped CdSe NPs showed a very sharp excitonic peak at 420 nm. Its very small full width at half maximum (18 nm) indicates very high quality of the CdSe NPs. Their absorption features experienced little change over a month, implying an excellent stability of the CdSe NPs. The synthesis conditions were very critical to the optical property and stability of the CdSe NPs: only those prepared at specific conditions (n(Se-precursor)/n(Cd-precursor) = 0.25-0.5, n(Cys)/n(Cd-precursor) = approximately 9, pH = approximately 12) showed very sharp absorption peaks and maintained an excellent stability against time. Under these conditions, the peaks always appear at nearly the same wavelength, indicating that these NPs are selectively stable and grow at a particular size and structure.
Center for Interdisciplinary Research, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.
Yeon-Su
YS
Park
Andriy
A
Dmytruk
Igor
I
Dmitruk
Noda
N
Yasuto
Atsuo
A
Kasuya
Motohiro
M
Takeda
Noriaki
N
Ohuchi
D019187:Cadmium Compounds / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D008027:Light; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D044367:Phase Transition; D012542:Scattering, Radiation; D018036:Selenium Compounds / Q000737:chemistry*; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
D019187:Cadmium Compounds; D046911:Macromolecular Substances; D018036:Selenium Compounds; D014867:Water; C058667:cadmium selenide