A simple method for making Lilliputian cups

In a report scheduled for the Nov. 16 issue of the ACS weekly Journal of Physical Chemistry B, researcher G. U. Kulkarni and colleagues report "a simple and straightforward" method for producing metal cups with a capacity measured in femtoliters. To show that the cups work as nanocontainers, Kulkarni's group filled some with fluorescent biomarkers and metal nanoparticles.

A femtoliter, which is one quadrillionth of a liter (1.1 quarts), may seem uselessly small; however, Kulkarni describes a growing need for ultrasmall containers in scientific research. Uses for such small vials range from holding nanoparticles to serving as nano inkwells for a technology termed "dip pen nanolithography."

The new method of producing the tiny cups involves blasting melts (viscous solutions) with a laser beam in a vacuum to produce droplets of molten metal that form into cuplike structures.

Although scientists previously have made even smaller containers, including some with a capacity of a zepto liter - one million times smaller than a femtoliter - the new method of producing the tiny cups has advantages, including simplicity, over previous methods, according to the researchers.

Source: American Chemical Society