Plastic coating makes chips biofriendly

Electronics usually don't mix well with biological material.

Sandia National Laboratories researchers have overcome the incompatibility with a microscopic laser designed to quickly measure and identify microorganisms and cell types without inhibiting biological processes.

The device is a tailored stack of materials that includes a light-emitting semiconductor surrounded by a polymer, or plastic material that protects cell membranes from the toxic semiconductor.

The device measures cells by shining light through them and analyzing the light that comes through the other side. The pattern shows the distribution of protein molecules and organelles within a cell. The method can be used to identify cancer cells and distinguish sickle from normal red blood cells; it can potentially identify specific bacteria, including antibiotic-resistant bacteria and different types of anthrax, according to the researchers.

Handheld diagnostic microlaser devices could be used in the field, including areas devastated by war or disaster. The device could also eventually enable surgeons to determine in real-time where a malignant tumor ends and healthy tissue begins, according to the researchers.

Handheld sensors could be practical within three years, according to the researchers. The work appeared in the October 2002 issue of the Journal of Biomedical Optics.