Nanoscale & Nanoscale Advances Blog

Indium tin oxide (ITO) nano-branches for application in transparent flexible electrodes (TFEs) have been made by researchers in Korea.

The team used a simple beam evaporation method to make single crystal ITO nano-branches, which show better conductivity, better thermal stability and significantly better mechanical flexibility compared to commercial ITO film.

Transparent conducting oxides are very attractive materials for TFEs as they overcome limitations of alternatives such as metallic nanowires and carbon-based nanostructures, but their mechanical brittleness is a drawback. The nano-branched structure is much more flexible, and has an improved production process requiring lower temperatures and offering larger synthesis areas.

TFEs pervade modern technologies as critical components of many optoelectronic devices, e.g. solar cells, displays and lighting devices. The much-improved mechanical flexibility of this nano-branched structure implies potential for broad applicability in optoelectronic devices.

Read the Nanoscale article:

Nano-branched transparent conducting oxide: Beyond the brittleness limit for the flexible electrode applications
Hak Ki Yu, Sungjun Kim, Bonhyeong Koo, Gwan Ho Jung, Bola Lee, Juyoung Ham and Jong-Lam Lee
Nanoscale, 2012, DOI: 10.1039/C2NR32228E

A system that enables controlled delivery of materials into a single cell without the need for highly specialised manual operation has been developed by US scientists.

The system is fully electrical, is based on double-barrel nanopipettes and is capable of injecting a controlled amount of material into a single cell. It uses a scanning ion conductance microscope (SICM) to position a nanopipette within a few hundred nanometres of the cell membrane. The amount of material delivered to the cell is controlled by the amplitude and duration of an applied voltage. The team injected human fibroblasts with carboxyfluorescein as a proof-of-principle experiment.

Traditional micropipettes suffer from several drawbacks, e.g. large size relative to typical cells, low cell viability following injection and requirement of skilled operator. More recently developed atomic force microscopy-based nanoinjectors are limited in terms of throughput and control of injection volumes.

This new system overcomes many of these concerns, including very good cell viability (70-100 %), with normal cell division observed 27 hours post-injection. In addition, the authors were able to inject two different dyes into the cells without any cross-talk observed between the two; this gives rise to the possibility of build in more chambers and customise specific cocktails of molecules for different cells.

Read the ‘HOT’ Communication hot of the press!

Voltage Controlled Nano-injection System for Single-cell Surgery
R. Adam Seger, Paolo Actis, Catherine Penfold, Michelle Maalouf, Boaz Vilozny and Nader Pourmand
Nanoscale, 2012, Accepted Manuscript
DOI: 10.1039/C2NR31700A

Nanoscale ‘HOT’ Article

Zhen Zhou and co-workers have synthesised and characterised a doughnut-like Ni(OH)₂–Co(OH)₂ composite for use in pseudocapacitors.

The specific capacitance for the first discharge of the composite was calculated as 2193 F g^-1 at a discharge current density of 2 A g^-1, which is significantly larger than the corresponding value of 1914 F g^-1 for pristine Ni(OH)₂ at the same current density. The composite also exhibited better cycling performance and rate capability than Ni(OH)₂.

This study has shown that the overall electrochemical performance is considerably enhanced for the doughnut-like Ni(OH)₂–Co(OH)₂ composite.

Read the Nanoscale Article today:

Preparation and electrochemical performances of doughnut-like Ni(OH)₂–Co(OH)₂ composites as pseudocapacitor materials
Jinxiu Li, Mei Yang, Jinping Wei and Zhen Zhou
Nanoscale, 2012, DOI: 10.1039/C2NR30936J

Fluorescent carbon dots, a new member of the carbon nanomaterial family, have been drawing attention for use as optoelectronic devices, biological labelling and biomedicine, as an alternative to metal containing quantum dots (nanocrystals).

Scientists in China have synthesised them in a green way: with low heat, in one pot, in water, using ascorbic acid as the precursor.

Read the ‘HOT’ Nanoscale article:

One-pot green synthesis of optically pH-sensitive carbon dots with upconversion luminescence
X Jia, J Li and E Wang,
Nanoscale, 2012, DOI: 10.1039/c2nr31319g

The first image of the structure of an Au₂₀ cluster has been captured by researchers in the UK. The team says that the cluster has a tetrahedral pyramid structure.

This particular structural arrangement had been proposed after gas-phase experiments and theoretical calculations, but this is the first time that real-space atomic resolution images using scanning transmission electron microscopy have proved its existence on a solid surface.

This is important because confirming the atomic structure is fundamental for understanding nanoparticle structures and for the cluster’s applications in, for example, heterogeneous catalysis.

Read the ‘HOT’ Nanoscale article today:

Direct atomic imaging and dynamical fluctuations of the tetrahedral Au20 cluster
Z W Wang and R E Palmer
Nanoscale, 2012, DOI: 10.1039/c2nr31071f