Water-soluble CdS Nanoparticles Research Articles

Synthesis of water soluble CdS nanoparticles and study of their DNA damage activity

This study reports a novel method for preparation of water soluble CdS nanoparticles using leaf extract of a plant, Asparagus racemosus. The extract of the leaf tissue which worked as a stabilizing and capping agent, assisted the formation of nanoparticles. Nanoparticles were characterized using a UV–vis spectrophotometer, Photoluminescence, TEM, EDAX, XRD and FT-IR. Transmission electron microscopy followed by selected area electron diffraction pattern analysis indicated the formation of spherical, polydispersed, crystalline, CdS of diameter ranging from 2 to 8nm. X-ray diffraction studies showed the formation of 111, 220 and 311 planes of face-centered cubic (fcc) CdS. EDAX analysis confirmed the presence of Cd and S in nanosphere. The cytotoxicity test using MTT assay as well as DNA damage analysis using comet assay revealed that synthesized nano CdS quantum dots (QDs) caused less DNA damage and cell death of lymphocytes than pure CdS nanoparticles.

PH-Dependent shape changes of water-soluble CdS nanoparticles

In this study, a one-pot route was illustrated to synthesize stable water-soluble CdS nanoparticles stabilized by poly-(4-styrenesulfonic acid-co-maleic acid) (PSSMA). The CdS nanoparticles synthesized in alkaline solutions (pH 10.0) were irregular and small in size (~1.1 nm), while those generated in acid solutions (pH 4.5) tended to aggregate to form larger particles (~74.5 nm). Some bridge-like CdS wires linking several CdS particles were observed by tuning the molar ratio of elemental Cd to S. The ligand-detachment mechanism has been proposed to be the main reason for the formation of CdS assemblies synthesized in acid solutions. Further, photoluminescence (PL) studies confirmed that the use of the PSSMA stabilizer induces incomplete quenching of PL emissions in an acid solution, but complete quenching in an alkaline solution.

A Facile Synthesis Route of Size Tunable CdS Quantum Dots with High Photoluminescence Yield

Water soluble CdS nanoparticles were synthesized by reacting CdCl2 with sodium thiosulphate solutions as sulphur precursor. The facile one-pot synthetic route produced tunable (2-10 nm) high quality QDs with narrow particle size distribution and enhanced quantum yields (QY).

Characterization of triglycine sulfate (TGS) crystals grown in water-soluble CdS nanoparticles dispersed in water

Single crystals of Triglycine Sulfate (TGS) were grown in water and also were grown in water-soluble CdS nanoparticles dispersed in water by solution method with slow evaporation technique at room temperature. Watersoluble CdS nanoparticles were synthesized by microwave-assisted solution method using the precursors such as cadmium sulfate, thioglycolic acid and ethylene diamine and they were used for the growth of CdS-added TGS crystals. The grown crystals were characterized by XRD technique, UV-visible spectral studies, measurement of density, microhardness studies, atomic absorptions studies. The effect of Cd 2+ ions on various properties of TGS crystals have been analyszed and reported.

Luminescence Study of Water-Soluble CdS Nanoparticles Produced by Femtosecond Laser Ablation at High Laser Fluence

Water-soluble CdS nanoparticles (NPs) with excellent colloidal stability were produced by femtosecond laser ablation at high laser fluence. The transmission electron microscope image of the obtained NPs exhibited a presence of two populations, characterized by low and high size dispersions, with different mean particle sizes. A comprehensive optical spectroscopy study of the NPs was carried out, and the results indicated a close correlation between the distribution properties and the luminescence characteristics. By analyzing the photoluminescence spectra of the CdS NPs synthesized under different focusing conditions, we revealed that the formation of the two-peak NPs distributions is related to the breakdown-induced plasma in water at such high laser fluence. However, this plasma-related ablation could manifest itself in the production of highly dispersed population, whereas the formation of the low-dispersed one is mainly attributed to the pure radiation-related ablation. This work will help us take advantage of the ultrapulse laser to synthesize favorable water-soluble semiconductors NPs for biosensing and labeling applications.

Water soluble CdS nanoparticles with controllable size prepared via femtosecond laser ablation

Small water soluble CdS nanocrystals (NCs) with excellent colloidal stability were prepared by femtosecond laser ablation of a bulk CdS target without using any surfactant. CdS NCs of different sizes ranging from 2.0 to 8.6 nm can be produced by simply adjusting the laser fluence at low values, which are just above the ablation threshold. The obtained CdS NCs show a relatively narrow size distribution, which gradually narrows as the laser fluence decreases, as can be seen in the transmission electronic microscopic images. UV-vis optical absorption, photoluminescence, and fluorescence lifetime were also used to characterize the NCs. These as-prepared small crystals show excellent water solubility and have good colloidal stability. Their size is easily controlled as well. Together, the above-mentioned properties make these NCs of interest for luminescence labeling and sensing applications.

Studies on fluorenscence resonance energy transfer between CdS nanoparticles and DOCAI dyes

The water-soluble CdS nanoparticles were synthesized in aqueous solution. A novel fluorescence resonance energy transfer (FRET) system with CdS nanoparticles as energy donors and 3,3′-diethyl-oxadicarbocyanine iodide (DOCAI) dyes as energy accepter has been developed.

Preparation and characterization of water-soluble CdS nanocrystals by surface modification of ethylene diamine

The water-soluble CdS nanoparticles were obtained by hydrogen bond between the cadmium-thiolate complex on the surface of CdS nanoparticles and ethylene diamine (anhydrous). The modified CdS nanoparticles enhanced its solubility in H 2O and alcohol. The ethylene diamine-capped CdS nanoparticles were characterized by Fourier Transform Infrared Spectroscopy (FTIR), photoluminescence (PL) and Ultraviolet–Visible absorption spectrum (UV–Vis spectrum). The absorption peak at 262 nm was observed, which belonged to ethylene diamine-modificated Cd-thiolate complex at the surface of as-grown CdS nanoparticles. The results of the PL spectra indicated that the modification of CdS nanoparticles reduced effectively the local surface-trap states. Based on the above results, a possible mechanism for the formation of the water-soluble CdS nanoparticles was discussed.

Synthesis, structure and spectroscopic characterization of water-soluble CdS nanoparticles

We present a facile approach for synthesizing bio-stabilized CdS nanoparticles in gram quantities. The particles were characterized by optical spectroscopy, Raman spectroscopy, soft X-ray emission spectroscopy, XRD, thermal and chemical analysis. The size of the particles is about 2.3 nm, with a CdS core of 1.3 nm diameter and an organic shell of 0.5 nm thickness which is thermally stable up to 200 °C. The chemical composition, surface termination, and optical properties are analysed.