Nanoscale & Nanoscale Advances Blog

Dongsheng Guan and Ying Wang of Louisiana State University report a novel way to prepare multilayered TiO₂ nanotube arrays. In this study, TiO₂ nanotubes grow at a steady ready under stable pH and ion-diffusion conditions but, when the voltage is first reduced and then subsequently increased again, a second layer of nanotubes can be grown on top of the first.

The work casts light on the mechanism of TiO₂ nanotube growth and could see applications from batteries to solar cells.

Read this HOT Nanoscale article today:

Synthesis and growth mechanism of multilayer TiO₂ nanotube arrays
Dongsheng Guan and Ying Wang
Nanoscale, 2012, DOI: 10.1039/C2NR30315A

Self-disinfecting surfaces that reduce the activity of influenza A, hepatitis C and E. coli have been developed by scientists from the US.

The team from UCLA used zinc-copper-indium nanocrystals to make surfaces that allow oxygen species and other free radicals to form under visible light illumination. These active species reduce influenza A activity up to 94% and hepatitis C up to 85%.

Read this HOT communication today:

Visible light powered self-disinfecting coatings for influenza viruses
Ding Weng , Hangfei Qi , Ting-Ting Wu , Ming Yan , Ren Sun and Yunfeng Lu
Nanoscale, 2012, DOI: 10.1039/C2NR30388D

Scientists in Germany, the US and Finland have used graphene membranes as highly sensitive sensor devices for molecules on the nanoscale.

The molecules are adsorbed onto the graphene’s surface and then molecular dynamics are used to measure mass and other physical properties. The team showed that they can detect specific “fingerprints” left by the molecules on the graphene surface, which can be identified by IR or Raman spectroscopy. As the molecule moves on the surface, these dynamical movements can be detected by a graphene-based drum (a nanoscale “ear” that can hear “sounds” produced by other molecules).

The device could be used for nanoelectronics or to improve atomic force microscopy-based techniques.

Read the full details of this exciting work today:

Nanoscale ear drum: Graphene based nanoscale sensors
Stanislav Avdoshenko , Claudia Gomes Rochaa and Gionarelio Cuniberti
Nanoscale, 2012, DOI: 10.1039/C2NR30097D

Deli Wang and co-workers’ paper on tree-like Si/ZnO nanowires which can be used as photoelectrodes in photoelectrochemical cells has been highlighted in ScienceDaily. The nanostructures show improved current density and H₂ evolution kinetics compared to planar Si/ZnO structures.

Read this exciting article in full:

3D branched nanowire heterojunction photoelectrodes for high-efficiency solar water splitting and H₂ generation
Ke Sun, Yi Jing, Chun Li, Xiaofeng Zhang, Ryan Aguinaldo, Alireza Kargar, Kristian Madsen, Khaleda Banu, Yuchun Zhou, Yoshio Bando, Zhaowei Liu and Deli Wang
Nanoscale, 2012, 4, 1515-1521
DOI: 10.1039/C2NR11952H

Chinese scientists have developed a protocol which allows them to detect the proteins present in latent fingerprints. The authors used silver nanoparticles functionalised with antibodies which could interact with relevant proteins in a fingerprint and studied the prints using surface-enhanced Raman spectroscopy (SERS). Mapping of the obtained SERS signals gave an image indicating the distribution of the proteins in the print.

The authors suggest this technique could be applied to medical diagnostics.

Read this HOT Nanoscale article today:

Detection of protein deposition on latent fingerprints by surface-enhanced Raman spectroscopy imaging
Lehui Lu, Wei Song, Zhu Mao, Xiaojuan Liu, Zhishi Li and Bing Zhao
Nanoscale, 2012, DOI: 10.1039/C2NR12030E

Chinese scientists studying the wings of the Trogonoptera Brookiana butterfly have discovered that the light trapping structures which cause the iridescent colours we see are caused by two distinct types of nanostructure one on the front and one on the back of the wing.

Understanding how these natural structures function can give great insight for engineering materials with these properties and could have applications from solar cells to stealth technology.

Read this HOT article in full:

Light Trapping Structures in Wing Scales of Butterfly Trogonoptera Brookiana
Zhiwu Han , shichao niu , Chunhui Shang , Zhenning Liu and Luquan Ren
Nanoscale, 2012
DOI: 10.1039/C2NR12059C 

Mercury pollution can cause major problems for the health of humans, fish and wildlife. Scientists based in Singapore now report a sensitive sensor for the Hg²⁺ ions present in aqueous environments which is also inexpensive and easy to produce. The system is based on Ag⁺-based nanoparticles the luminescence of which is quenched in the presence of mercury ions.

Read this HOT Nanoscale communication today:

Highly luminescent Ag⁺ nanoclusters for Hg²⁺ ion detection
Xun Yuan , Teik Jin Yeow , Qingbo Zhang , Jim Yang Lee and Jianping Xie
DOI: 10.1039/C2NR11999D