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Hybrid Lead sulfide-graphene Quantum Dots: Optoelectronic Properties and Cytotoxicity Evaluation

Ayoubi, Mahdi | 2015

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 50867 (07)
  4. University: Sharif University of Technology
  5. Department: Materials Science and Engineering
  6. Advisor(s): Simchi, Abdolreza
  7. Abstract:
  8. In recent years, quantum dots specially NIR QDs like lead sulfide have attracted a lot of attentions in various bioapplications such as bioimaging, stem cell tracking, etc. However, these materials are generally synthesized by using organic lagands like oleic acid which is not appropriate for bioapplications. Moreover, the cytotoxicity of these materials have severely restricted their applications. In this research, lead sulfide quantum dots were synthesized via a hot injection route. The nanocrystals had an average size of 3 nm passivated with oleic acid ligands and graphene nanosheets. Excitonic and photoluminescence peaks were observed in wavelengths of 950 and 1100 nm, respectively. Graphene quantum dots as capping ligands were synthesized through electrolysis of graphite having the size and thickness of less than 10 and 1 nm, respectively. Capping of the PbS nanocrystals by graphene nanosheets provided water dispersiable quantum dots with high PL emission. Biocompatibility tests showed no toxicity of quantum dots on MCF7 cell using consentrations less than 0.5 µM
  9. Keywords:
  10. Graphene ; Quantum Dot ; Lead Sulfide ; Hybrid Nanoparticles ; Nanoparticle Synthesis