Single-cell enzyme monitoring?

A new technique to rapidly detect enzyme activity published online August 8 in Nature Biotechnology is sensitive enough to identify reactions from as few as 500 molecules, according to researchers at the University of Strathclyde, Glasgow, who say their method could potentially detect multiple enzyme activities simultaneously and at levels found within single cells.

"We think we can probably apply the technology to most enzyme classes," researcher Barry Moore said of the method, which employs surface-enhanced resonance Raman scattering (SERRS). In SERRS, the target compound is adsorbed onto a roughened metal surface, producing an enhanced vibrational spectrum of the target, characterized by multiple sharp peaks, that serves as a fingerprint. The research team used a suspension of citrate-reduced silver particles roughly 40 nanometers in diameter as their metal surface.

The key to detecting enzyme activities at ultra-low levels is a newly devised class of substrates covered by a University of ...