Content provided in partnership with

Litmus test gets tiny

By coating a nanoscale glass ball with gold and studding that metal with a forest of light-sensitive molecules, researchers in Texas have created what they say is the world's first nanoscale pH meter. The litmus paper familiar from high-school chemistry class and other pH meters gauge how acidic or basic a solution is.

Injected deep into living tissue, the new nanobauble could take the chemical pulse of a single cell, potentially signaling conditions such as cancer or organ rejection, the inventors suggest.

The molecules of para-mercatobenzoic acid (pMBA) that make up the device's light-sensitive forest emit radiation when hit by an infrared laser beam. The spectrum of the pMBA's infrared emissions changes subtly in response to the pH of the surrounding fluid. The gold-coated core of the device amplifies the emissions.

Most Popular Articles in Reference: The importance of understanding organizational culture; Credit card attitudes and behaviors of college students; What factors attract foreign direct investment?; Libraries Need Relationship Marketing - mutual interest marketing concept, ...; How to set performance goals: employee reviews are more than annual critiques; More »

"It's a high-precision device," says Naomi J. Halas of Rice University in Houston, who led its development. Injected into tissue, such meters could enable physicians or biology researchers to monitor cell pH by shining a laser on cells of interest and analyzing the return signals, she adds.

Halas and her colleagues describe their invention in an upcoming Nano Letters. --P.W.

Technology Industry

Litmus test gets tiny

Science News, July 29, 2006

Find Research Guides for:

Find Featured Titles for: Technology

Most Popular Articles in Reference

Most Popular Publications in Reference