Highly monodispersed CdSe quantum dots (QDs) were prepared without an injection procedure. A series of Cd salts of long chain fatty acids, including Cd-myristate (C14), Cd-palmitate (C16) and Cd-stearate (C18) was prepared, and all metallic precursors and surfactants were mixed together followed by increasing the temperature in a controlled manner. The reaction resulted in highly monodisperse and bright zinc blende QDs. In addition, the effects of specific ligands which have been known to lead anisotropic growth of the nanocrystals in the injection method were investigated. The use of alkyl phosphonic acid and alkyl amine was found to produce extremely monodisperse CdSe QDs with a high quantum yield. This procedure was proven to be able to yield a large quantity of zinc blende CdSe QDs (2 g) in a one-pot reaction. The use of a controlled amount of tetradecylphosphonic acid and octadecylamine resulted in tetrapod- and match-shaped QDs, the first reported by a non-injection method. These results clearly demonstrate that appropriate combination of precursors can provide high quality of CdSe nanocrystals in terms of quantum yield, monodispersity and shape control by a non-injection method.
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http://dx.doi.org/10.1088/0957-4484/24/14/145601 | DOI Listing |
Anal Chem
December 2024
Key Laboratory of Optic-Electric Sensing and Analytical Chemistry for Life Science, MOE, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, P. R. China.
The classical electrochemiluminescence (ECL) reagent Ru(bpy) was first doped into CdSe QDs to prepare novel dual-potential color-resolved luminophore Ru-CdSe QDs. Ru-CdSe QDs emitted a strong red ECL signal at a positive potential with coreactant TPrA and a strong green ECL signal at a negative potential with coreactant KSO. As a proof-of-concept application, this work introduced Ru-CdSe QDs into a dual-channel closed bipolar electrode (CBPE) system to construct an ECL biosensor for simultaneous detection of chloramphenicol (CAP) and kanamycin (KAN).
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States.
Time-resolved single molecule localization microscopy (TR-SMLM) with a 2 × 2 pixel fiber optic array camera was combined with time-correlated single photon counting (TCSPC) to obtain super-resolved fluorescence lifetime images of individual Cy3 dye molecules and individual colloidal CdSe/CdS/ZnS core/shell/shell semiconductor quantum dots (QDs). The characteristic blinking and bleaching behavior of the Cy3 and the blinking behavior of the QD emitters were used as distinguishing optical characteristics to isolate them and determine their centroid locations with spatial resolution below the optical diffraction limit. TCSPC was used to characterize the fluorescence lifetime and intensity corresponding to each emitter location.
View Article and Find Full Text PDFNano Lett
January 2025
Key Laboratory of Advanced Display and System Applications Education of Ministry, Shanghai University, 149 Yanchang Road, Shanghai 200072, China.
Indium phosphide (InP) quantum dots (QDs) are promising alternative heavy-metal CdSe QDs for light-emitting diode (LED) application. However, their highly reactive core surface is prone to oxidation, which reduces the photoluminescence quantum yield (PL QY) and impedes subsequent shell growth. Traditional etching methods using HF aqueous solution are problematic as water can induce reoxidation during or after etching.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Department of Physics and Meteorology, School of Sciences, Sao Paulo State University (UNESP), Bauru, Sao Paulo 17033-360, Brazil.
The presence of toxic dyes in industrial waste dramatically diminishes the beneficial effects of remediation efforts. To overcome the hazardous impacts of dyes on biodiversity and environment, we integrated polymers into nanoparticles to substantially enhance their functionality and performance. 2 and 4 wt% of chitosan (CS) and 3 wt% of polyacrylic acid (PAA) doped cadmium selenide (CdSe) nanostructures (NSs) were prepared by co-precipitation approach.
View Article and Find Full Text PDFLuminescence
December 2024
School of Biotechnology, KIIT University, Bhubaneswar, Odisha, India.
This study presents a mild, one-pot synthetic approach for the synthesis of multicolor, water soluble, photo luminescent CdS and CdSe quantum dots (QDs). To achieve this goal, cyclic peptides containing cysteine residues are rationally designed and synthesized. Among the peptides tested, those containing two cysteine residues exhibit superior stabilizing properties, ensuring the solubility and long-term stability of the QDs in aqueous solutions for several months.
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