Friday, April 16, 2010

This week in nanotechnology, April 16, 2010

A team of MIT researchers has found a novel way to mimic the process by which plants use the power of sunlight to split water and make chemical fuel to power their growth. In this case, the team used a modified virus as a kind of biological scaffold that can assemble the nanoscale components needed to split a water molecule into hydrogen and oxygen atoms.

A study released this week suggests that anti-cancer chemotherapies which use nanoparticles to deliver drugs deep inside tumor tissue will be more effective if the particles are positively electrically charged because they are taken up to a greater extent by proliferating cells.

atomic-scale black holes
Researchers invented 2-nanometer core gold particles, designated “payload” in the cartoon above, which can be coated with different surface materials such as green fluorescent dye (pictured) or anti-cancer drugs, giving them “tunable” properties and functionalities. The scientists found that positively charged gold nanoparticles crossed the cell membrane more readily than negatively charged particles, indicating a promising new approach for improving drug delivery to the majority of cells within tumors.

In an electrifying first, Stanford scientists have plugged in to algae cells with an ultrasharp nano-electrode and harnessed a tiny electric current. They found it at the very source of energy production - photosynthesis, a plant's method of converting sunlight to chemical energy. It may be a first step toward generating "high efficiency" bioelectricity that doesn't give off carbon dioxide as a byproduct, the researchers say.

Scientists create 'molecular paper' just two molecules thick. Two-dimensional, “sheet-like” nanostructures are commonly employed in biological systems such as cell membranes, and their unique properties have inspired interest in materials such as graphene. Now, Berkeley Lab scientists have made the largest two-dimensional polymer crystal self-assembled in water to date. This entirely new material mirrors the structural complexity of biological systems with the durable architecture needed for membranes or integration into functional devices.

Researchers have found a new method for generating tunable wavelengths, as well as more easily switching back and forth between two wavelengths, employing quantum-dot lasers. Prospective application fields are biomedicine and nanosurgery. Under the EU’s “FAST-DOT” project, the researchers have recently discovered that, under some circumstances, quantum-dot lasers do emit first short-wavelength photons and then long-wavelength photons.

A new fabrication technique, combined with well-developed carbon chemistry, enables the synthesis of solution-processable black graphene quantum dots with uniform size through solution chemistry. These graphene quantum dots can be used as sensitizers for solar cells and brinf all-carbon solar cells a step closer.