Nanoscale & Nanoscale Advances Blog

The initial idea, fueling part of the push for nanotechnology, was that electronic circuits could be self-assembled by choosing the correct combination of molecular building blocks. This paper from the group of Oren A. Scherman at University of Cambridge shows how small molecular circuits with gold contacts can be self-assembled.

Molecular interactions between cucurbit[8]urils hosts and two—an electron deficient and an electron rich—guests allow for the end-to-end linking of multiple gold nanorods. While several examples of end-to-end linking of gold nanorods have been published, see for example work by Kumar and by Jain, this supramolecular approach is interesting as it allows for processing in water.

It will be interesting to see what the next paper will bring. Is the next step more complex self-assembled structures or to investigate the potential of these structure by contacting the gold nanorods and investigating the electron transport characteristics?

by Dr Thomas Just Sørensen

Supramolecular alignment of gold nanorods via cucurbit[8]uril ternary complex formation
Samuel T. Jones, Jameel M. Zayed and Oren A. Scherman
Nanoscale, 2013, 5, 5299-5302
DOI: 10.1039/C3NR01454A

Research published in Nanoscale describes the development of a micro-woven tin oxide cloth that enables the design of flexible, self-powered detectors for environmental monitoring.

Chinese scientists fabricated the material, which acts as both a battery anode and a light sensor, using a sacrificial carbon cloth as a template. The team used this to grow tin oxide nanoparticles which form hollow tubes identical in structure to the woven carbon when the carbon cloth is removed at high temperatures. Tin oxide is a wide band gap semi-conductor with high quantum efficiency in the UV region, making the material a good substrate for both battery electrodes and light detection.

The scientists showed that two of the tin oxide layers can be integrated into one highly flexible, self-powered photodetector that shows comparable performance when compared to non-foldable devices with external power supplies. No change in light detection or power generation occurs when the cloth is folded.

Read this exciting article today:

SnO₂-microtubes-assembled cloth for fully flexible self-powered photodetector nanosystems
Xiaojuan Hou, Bin Liu, Xianfu Wang, Zhuoran Wang, Qiufan Wang, Di Chen and Guozhen Shen
DOI: 10.1039/C3NR02300A

Hao Dong, Ling-Dong Sun and Chun-Hua Yan review the energy upconvertion potential of lanthanide doped minerals, in bulk and in nanocrystals/nanoparticles. The plethora of excited state in lanthanide ions can be exploited in single metal energy upconverters and in multimetellic systems, where the number of populated excited states is increased significantly. The paper is an excellent starting point for the people interested in lanthanide energy upconvertion.

My first encounter with energy upconvertion was for thulium ions in solution, where high fluency irradiation made several processes possible, which never would take place in the world of linear photophysics I usually inhabit. The possible processes multiply in nanocrystalline matrices with multiple lanthanide ions present. Dong et al. have kept their sights straight and produced an concise account of the possible mechanism for energy upconversion and on how to identify them. The road to a low fluency energy upconverting system may prove to be long, but papers like this makes sure that it will be interesting.

by Dr Thomas Just Sørensen

Read this Minireview article in Nanoscale today:

Basic understanding of the lanthanide related upconversion emissions
Hao Dong, Ling-Dong Sun and Chun-Hua Yan
Nanoscale, 2013, 5, 5703-5714
DOI: 10.1039/C3NR34069D