11-06/07 :: June/July 2011

nanotimes News in Brief Superconducting Nanowire Single-Photon Detectors (SNSPDs)

Researchers at Massachusetts Institute of Technology, USA, and Kavli Institute of Nanoscience, Delft University of Technology, The Netherlands, present 20 and 30 nm nanowire-width Superconducting Nanowire Single-Photon Detectors (SNSPDs), which were more robust to constrictions and more re- sponsive to 1550-nm-wavelength photons than standard SNSPDs. They implemented a parallel-nanowire structure to read out ultranarrow-nanowire detectors with room-temperature electronics.

Francesco Marsili, Faraz Najafi, Eric Dauler, Francesco Bellei, Xiaolong Hu, Maria Csete, Richard J. Molnar, and Karl K. Berggren: Single-Photon Detectors Based on Ultranarrow Superconducting Nanowires, In: NANO Letters, Vol. 11, Issue 5, May 11, 2011, Pages 2048-2053, DOI:10.1021/nl2005143: http://dx.doi.org/10.1021/nl2005143

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Core-shell Nanoparticles

MIT researchers employed a modular design for the high-throughput study of 1,536 structurally distinct nanoparticles with cationic cores and variable shells. This enabled elucidation of complexation, internali- zation, and delivery trends that could only be learned through evaluation of a large library. Using robotic automation, epoxide-functionalized block polymers were combinatorially cross-linked with a diverse library of amines, followed by measurement of molecular weight, diameter, RNA complexation, cellular internalization, and in vitro siRNA and pDNA delivery.

Daniel J. Siegwart, Kathryn A. Whitehead, Lutz Nuhn, Gaurav Sahay, Hao Cheng, Shan Jiang, Minglin Ma, Abigail Lytton-Jean, Arturo Vegas, Patrick Fenton, Christopher G. Levins, Kevin T. Love, Haeshin Lee, Christina Cortez, Sean P. Collins, Ying Fei Li, Janice Jang, William Querbes, Christopher Zurenko, Tatiana Novobrantseva, Robert Langer, and Daniel G. Anderson: Combinatorial synthesis of chemically diverse core-shell nanoparticles for intracellular delivery, In: PNAS Early Edition, July 22, 2011, DOI:10.1073/pnas.1106379108: http://dx.doi.org/10.1073/pnas.1106379108