By Peter Weiss
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.