Direct synthesis of aqueous CdSe/ZnS-based quantum dots using microwave irradiation

Details

• Personal Author:
  Dutta PK ; Nagy A ; Schumacher W ; Waldman WJ
• Description:
  This study focuses on an aqueous one-pot method for synthesis of CdSe/ZnS core/shell QDs using microwave radiation. The novelty of the study is the use of Zn(NH3)4 2+ as the zinc source. Using an initial solution with the composition Cd1Se1Zn6MPA20, the QDs obtained upon heating at 160 degrees C for 60 min were not high quality, as evidenced by a quantum yield of 1.5%, due to the poor interface between the core and shell. Postsynthesis UV irradiation of the as-prepared QDs for 30 min could be used to improve the quantum yield to 22%, but the technique is not practical for large-scale applications. By increasing the amount of Cd2+ in the initial solution to Cd4Se1Zn4MPA20, we formed CdSe/CdS/ZnS QDs after heating at 150 degrees C for 90 min, which contained less interfacial trap-states and as a result, had a higher quantum yield of 13%. These QDs were characterized by powder diffraction, electron microscopy, and X-ray photoelectron spectroscopy. Uptake of the microwave-optimized QDs by alveolar macrophages was compared in a side-by-side study against commercial QDs, QDot585. Despite having a lower relative quantum yield (13%) as compared to the commercial QDs (65%), the microwave-synthesized QDs at 20 nM concentrations were readily detected within the macrophages after 20 min of incubation. [Description provided by NIOSH]
• Subjects:
  Cadmium Inorganic Chemicals Occupational Health Radiography Safety Spectrum Analysis Sulfur Compounds Zinc Compounds
• Keywords:
  Biological-function Cadmium-compounds Inorganic-compounds Nanotechnology Selenium-compounds Spectrographic-analysis Sulfur-compounds X-ray-analysis Zinc-compounds
• ISSN:
  1932-7447
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  113
• Issue:
  28
• NIOSHTIC Number:
  nn:20041643
• Citation:
  J Phys Chem C 2009 Jul; 113(28):12132-12139
• Contact Point Address:
  Prabir K. Dutta, Departments of Chemistry and Pathology, The Ohio State UniVersity, Columbus, Ohio 43210
• Email:
  dutta@chemistry.ohio-state.edu
• Federal Fiscal Year:
  2009
• Performing Organization:
  Ohio State University
• Peer Reviewed:
  False
• Start Date:
  20060801
• Source Full Name:
  Journal of Physical Chemistry C
• End Date:
  20100731
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:56b0289f3c41e538ce337cee70da93f7ae81bf82c84a8437788ba74eb3c4c797ceb12f4f48e36f5c1e7c481aa489af907fd8d0b59d3e7ec3b4ddcaff5f2236ea
• Download URL:
  https://stacks.cdc.gov/view/cdc/194145/cdc_194145_DS1.pdf
• File Type:
  [PDF - 2.45 MB ]