High luminescent L -cysteine capped CdTe quantum dots prepared at different reaction times

Kiprotich, Sharon; Onani, Martin O.; Dejene, F.B.

doi:10.1016/j.physb.2017.07.037

Cited by 14 publications

(11 citation statements)

References 30 publications

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“…Also, the production of well‐complexed Cd + ions and CdSe NPs vary with different cadmium sources. This leads to agglomeration of the as‐prepared CdSe NPs as observed in the SEM images thus promoting Ostwald ripening process to take place in the NPs, and hence, the growth of the NPs . All these contributing factors led to different FWHM and crystallite size values obtained in this study.…”

Section: Resultsmentioning

confidence: 99%

Structural and optical properties of novel CdSe nanoparticles produced via a facile synthetic route: Studies on the effects of cadmium sources

Kiprotich

Dejene

Onani

2019

Surface & Interface Analysis

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We report on the successful synthesis of CdSe nanoparticles (NPs) via a facile aqueous approach. Investigation on the effects of various cadmium sources in the precursor solution on the CdSe NPs is discussed. The structural and morphological properties characterized by the X‐ray diffraction (XRD) and scanning electron microscope (SEM) displayed good features of the as‐prepared CdSe NPs. The XRD pattern displayed a pure zinc blende crystal structure for all samples, with the most crystalline sample observed for CdSe NPs prepared using anhydrous cadmium chloride. The estimated crystallite sizes were below 6 nm for all the CdSe NPs samples. Mixed shapes of spherical and nanorods of varying sizes were observed from the SEM images for the as‐prepared NPs prepared using different cadmium sources. The optical studies conducted by photo‐spectroscopy pointed out the CdSe NPs prepared using anhydrous cadmium chloride gave the best optical properties. The emission wavelengths were in the range 565 to 574 nm while the optical band gaps were in the range 2.94 to 3.23 eV for all the as‐prepared CdSe NPs samples. All the samples, however, displayed quantum confinement effects giving room for further fabrication and engineering to suit specific applications in the biological field. The obtained results demonstrated that aqueous phase synthetic route employed in this study could be successfully adopted for production of high‐quality CdSe NPs because of its facile and inexpensive nature.

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Section: Resultsmentioning

confidence: 99%

Structural and optical properties of novel CdSe nanoparticles produced via a facile synthetic route: Studies on the effects of cadmium sources

Kiprotich

Dejene

Onani

2019

Surface & Interface Analysis

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“…The PL spectra of as‐grown CdTe NPs taken at room temperature were measured using an optical spectrophotometer. Different excitation values give emission wavelengths of varied intensity . The excitation wavelengths for all the CdTe NPs samples were set at 400 nm.…”

Section: Resultsmentioning

confidence: 99%

Capping Ligand Influence on the Structural, Optical and Luminescence Properties of CdTe Nanoparticles Prepared by a Simple Wet Chemical Process

2019

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The nature of the capping ligands used and the strength of their interactions with the surface atoms of the nanoparticles (NPs) impact greatly on the material properties and the stability of the resulting NPs. The structural analysis revealed that all the as-prepared CdTe NPs samples had a zinc blende crystal structure of different phases. The glutathione and L-cysteine capped CdTe NPs had the same zinc blende phase (JCPDS no. 75-2086) while thioglycolic acid capped and co-capped CdTe NPs possessed another zinc blende phase (JCPDS no. 75-2083). The calculated crystallite sizes were in the range 2-26 nm for all the samples. The optical spectroscopy studies showed various properties when different capping ligands were used. The band gap energies for all the as-prepared CdTe NPs confirmed the results obtained from the X-ray diffraction. The band gap energies were in the range of 2.39-3.34 eV for all the as-prepared CdTe NPs.[a] Dr.

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“…There is a reasonable, significant crystal growth shift between 5-30 min that is caused by the growth of the QDs during the time gap between aliquot sample collections. [20] Towards the end of the 30 min of the crystal growth, there is slow growth and the nanocrystals are less mono-dispersed. Self-aggregation of the nanocrystals occurs towards the end of the reaction possibly due to the reduced reaction vessel volume as the amount of the nanocrystals increased.…”

Section: Effects Of Synthesis Temperatures On the Growth Of Cdse/znse...mentioning

confidence: 99%

Effects of Reaction Temperature and Cadmium Source on the Optical, Morphological and Cytotoxic Properties of CdSe/ZnSe Quantum Dots

Nkaule,

Kiprotich,

Brandt

et al. 2023

ChemistrySelect

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The colloidal synthesis of CdSe/ZnSe core/shell quantum dots (QDs) under nitrogen gas flow is presented in this study. The optical, morphology and structural properties of CdSe/ZnSe core/shell QDs are varied by changing the growth temperature and the cadmium source (Cd2+). The Fourier transform infra‐red studies validate that CdSe/ZnSe QDs capped with functional −COOH groups were formed. The morphological and composition studies conducted using high resolution transmission microscope, selected area electron diffraction andenergy dispersive spectroscope confirmed the formation of pure and mono‐disperse QDs while photoluminescence and ultra‐violet visible spectroscopy displayed their improved fluorescent properties. Caco‐2 cell line was cultured from colon cancer and cytotoxic studies were conducted to test for cell viability of various capped 3‐MPA CdSe/ZnSe QDs at various concentrations. The formed CdSe/ZnSe QDs prominently bear the zinc‐blende structure with their particle size lying well below the Bohr excitation radii. Their hydrophilic nature and the availability of functional groups on the CdSe/ZnSe QDs makes them excellent potential labeling and therapeutic agents for the colon cancer disease diagnosis.

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High luminescent L -cysteine capped CdTe quantum dots prepared at different reaction times

Cited by 14 publications

References 30 publications

Structural and optical properties of novel CdSe nanoparticles produced via a facile synthetic route: Studies on the effects of cadmium sources

Structural and optical properties of novel CdSe nanoparticles produced via a facile synthetic route: Studies on the effects of cadmium sources

Capping Ligand Influence on the Structural, Optical and Luminescence Properties of CdTe Nanoparticles Prepared by a Simple Wet Chemical Process

Effects of Reaction Temperature and Cadmium Source on the Optical, Morphological and Cytotoxic Properties of CdSe/ZnSe Quantum Dots

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