A shocking new discovery

By observing how tiny specks of crystal move through the layers of a biological membrane, a team of University of Wisconsin-Madison electrical and computer engineers has devised a new method for investigating living systems on the molecular level. The discovery could lead to an entirely new level of manipulation, imaging and understanding of the inner workings of cells.

The specks are known as quantum dots or inorganic semiconductor nanocrystals. These dots are so small that the addition or removal of electrons changes the properties of the dot. The team, including Electrical and Computer Engineering Professors Dan van der Weide and Robert Blick with researchers Sujatha Ramachandran and George Kumar, found that by applying voltages to a solution of quantum dots and membranes similar to those of living cells, the dots would be pressed into the membranes. The dots formed rings, which in turn acted as portals in the membranes. These artificial portals or pores could enable a method of investigating living systems by means of semiconductor technology that until now could be theorised but not directly observed.