Nanotechnology

New physical chemistry study findings have been reported by S. Sadhu and co-researchers

  2008 NOV 24 - (VerticalNews.com) -- "We demonstrate strong evidence of shape-dependent efficient resonance energy transfer between CdS quantum dots (QDs) and quantum rods (QRs) (donor) to Nile Red dye (acceptor). We also report a simple solution-based method for the preparation of high quality CdS QDs and CdS QRs at relatively low temperature," scientists in Calcutta, India report.

  "The observed quenching of PL intensities are 78.8% and 63.8% for Cds Qds and QRs, respectively in the presence of Nile Red dye. The calculated energy-transfer efficiencies are 45% and 19% from QDs and QRs to dyes, respectively. The energy transfer varies with changing the shape of the nanoparticles. The estimated Forster distances (R-0) are 37.8 and 33.8 angstrom for CdS QDs and QRs, respectively. In the present study, the estimated distances (r) between one donor and one acceptor are 39.1 and 43.1 angstrom for QDs and QRs, respectively using the efficiency of Forester resonance energy transfer (FRET) which depends on the inverse sixth power of the distance of separations between one nanocrystal and one dye molecule. Considering single donor and multiple acceptors interactions, the calculated average distances (r(n)) between the donor and acceptor are 47.7 and 53.9 angstrom for QD's and QR's, respectively," wrote S. Sadhu and colleagues.

  The researchers concluded: "The steady-state and time-resolved spectroscopic analysis of nanoassemblies confirm the formation of one donor and multiple acceptors."

  Sadhu and colleagues published their study in Chemphyschem (Donor-acceptor systems: Energy transfer from US quantum dots/rods to Nile Red dye. Chemphyschem, 2008;9(14):2052-2058).

  For more information, contact A. Patra, Indian Association Cultivat Science, Dept. of Materials Science, Calcutta 700032, India.

  Publisher contact information for the journal Chemphyschem is: Wiley-V C H Verlag GmbH, PO Box 10 11 61, D-69451 Weinheim, Germany.

  Keywords: Emerging Technologies, Nanoassemblies, Nanocrystal, Nanoparticle, Nanotech, Nanotechnology, Physics, Quantum Dots, Quantum Physics, Quantum RodsPhysical Chemistry.

  This article was prepared by VerticalNews Nanotechnology editors from staff and other reports. Copyright 2008, VerticalNews Nanotechnology via VerticalNews.com.