Synthesis and Characterization of High-Quality Water-Soluble Near-Infrared-Emitting CdTe/CdS Quantum Dots Capped by N-Acetyl-l-cysteine Via Hydrothermal Method

The synthesis of water-soluble near-infrared (NIR)-emitting quantum dots (QDs) in aqueous solution has received much attention recently. However, the stabilizer 3-mercaptopropionic acid, commonly used in the synthesis of NIR-emitting QDs, is notorious for its toxicity and awful odor. Here we chose thiol ligand N-acetyl-l-cysteine (NAC) as the ideal stabilizer and have successfully employed it to synthesize high-quality NIR-emitting CdTe/CdS QDs in a one-step process via a simple hydrothermal route. NAC possesses favorable properties such as nontoxic, nonvolatile, inexpensive, and good water-solubility. Our as-prepared NIR-emitting CdTe/CdS QDs exhibit high photoluminescence quantum yields (45−62%), narrow full-width at half-maximum, and high photostability, thanks to the formation of a protective CdS shell on the CdTe core through the decomposition of NAC in the hydrothermal route under high temperature. The prepared QDs can be applied for bioimaging due to its excellent water-solubility and biological co...

[1]  ller,et al.  Relations between the Photoluminescence Efficiency of CdTe Nanocrystals and Their Surface Properties Revealed by Synchrotron XPS , 2003 .

[2]  Jia Guo,et al.  Synthesis of high-quality near-infrared-emitting CdTeS alloyed quantum dots via the hydrothermal method , 2007 .

[3]  Changqing Zhu,et al.  Aqueous synthesis of type-II core/shell CdTe/CdSe quantum dots for near-infrared fluorescent sensing of copper(II). , 2008, The Analyst.

[4]  D. Pang,et al.  Direct electrochemistry and electrocatalysis with hemoglobin in water-soluble quantum dots film on glassy carbon electrode. , 2005, Chemical communications.

[5]  Yuhong Xu,et al.  High-Quality and Water-Soluble Near-Infrared Photoluminescent CdHgTe/CdS Quantum Dots Prepared by Adjusting Size and Composition , 2007 .

[6]  Efros.  Luminescence polarization of CdSe microcrystals. , 1992, Physical review. B, Condensed matter.

[7]  Nicholas A. Kotov,et al.  Preparation of nanoparticle coatings on surfaces of complex geometry , 2003 .

[8]  L. James,et al.  Effect of N-acetylcysteine on acetaminophen toxicity in mice: relationship to reactive nitrogen and cytokine formation. , 2003, Toxicological sciences : an official journal of the Society of Toxicology.

[9]  John V Frangioni,et al.  Size series of small indium arsenide-zinc selenide core-shell nanocrystals and their application to in vivo imaging. , 2006, Journal of the American Chemical Society.

[10]  J. Critchley,et al.  Intravenous N-acetylcysteine: still the treatment of choice for paracetamol poisoning. , 1979, British medical journal.

[11]  Xiaogang Peng,et al.  Size-dependent dissociation pH of thiolate ligands from cadmium chalcogenide nanocrystals. , 2005, Journal of the American Chemical Society.

[12]  Hassan S. Bazzi,et al.  Differences in subcellular distribution and toxicity of green and red emitting CdTe quantum dots , 2005, Journal of Molecular Medicine.

[13]  Assaf Aharoni,et al.  Synthesis of InAs/CdSe/ZnSe core/shell1/shell2 structures with bright and stable near-infrared fluorescence. , 2006, Journal of the American Chemical Society.

[14]  Mingyuan Gao,et al.  Enhancement Effect of Illumination on the Photoluminescence of Water-Soluble CdTe Nanocrystals: Toward Highly Fluorescent CdTe/CdS Core−Shell Structure , 2004 .

[15]  One-Step Synthesis of High-Quality Gradient CdHgTe Nanocrystals: A Prerequisite to Prepare CdHgTe−Polymer Bulk Composites with Intense Near-Infrared Photoluminescence , 2008 .

[16]  N. Zhang,et al.  Ultrafast synthesis of highly luminescent green- to near infrared-emitting CdTe nanocrystals in aqueous phase , 2008 .

[17]  A. Alivisatos.  Semiconductor Clusters, Nanocrystals, and Quantum Dots , 1996, Science.

[18]  M. Bawendi,et al.  (CdSe)ZnS Core-Shell Quantum Dots - Synthesis and Characterization of a Size Series of Highly Luminescent Nanocrystallites , 1997 .

[19]  A. Tunek,et al.  Effects of N-acetylcysteine stereoisomers on oxygen-induced lung injury in rats. , 1995, Chemico-biological interactions.

[20]  Shengshui Hu,et al.  A hydrogen peroxide biosensor based on the direct electrochemistry of hemoglobin modified with quantum dots , 2007, JBIC Journal of Biological Inorganic Chemistry.

[21]  Shuming Nie,et al.  Alloyed semiconductor quantum dots: tuning the optical properties without changing the particle size. , 2003, Journal of the American Chemical Society.

[22]  W. Webb,et al.  Water-Soluble Quantum Dots for Multiphoton Fluorescence Imaging in Vivo , 2003, Science.

[23]  Huibi Xu,et al.  Use of ester-terminated polyamidoamine dendrimers for stabilizing quantum dots in aqueous solutions. , 2006, Small.

[24]  M. Kovalenko,et al.  Colloidal HgTe nanocrystals with widely tunable narrow band gap energies: from telecommunications to molecular vibrations. , 2006, Journal of the American Chemical Society.

[25]  D. Boothe,et al.  A possible mechanism of gastrointestinal toxicity posed by mycophenolic acid. , 2003, Pharmacological research.

[26]  Shimon Weiss,et al.  Hybrid approach to the synthesis of highly luminescent CdTe/ZnS and CdHgTe/ZnS nanocrystals. , 2004, Journal of the American Chemical Society.

[27]  N. Sommerdijk,et al.  Highly luminescent CdTe/CdSe colloidal heteronanocrystals with temperature-dependent emission color. , 2007, Journal of the American Chemical Society.

[28]  Sung Ju Cho,et al.  Quantum dot-induced cell death involves Fas upregulation and lipid peroxidation in human neuroblastoma cells , 2007, Journal of nanobiotechnology.

[29]  Jia Guo,et al.  Systematic study of the photoluminescence dependence of thiol-capped CdTe nanocrystals on the reaction conditions. , 2005, The journal of physical chemistry. B.

[30]  Xiaogang Peng,et al.  Formation of High Quality InP and InAs Nanocrystals in a Noncoordinating Solvent , 2002 .