Gold nanocluster arrays developed at A*STAR are well suited
for commercial applications of a high-performance sensing technique.
Cancer, food pathogens and biosecurity threats can all be
detected using a sensing technique called surface enhanced Raman spectroscopy
(SERS). To meet ever-increasing demands in sensitivity, however, signals from
molecules of these agents require massive enhancement, and current SERS sensors
require optimization. An A*STAR-led research team recently fabricated a
remarkably regular array of closely packed gold nanoparticle clusters that will
improve SERS sensors.
So-called ‘Raman scattering’ occurs when molecules scatter
at wavelengths not present in the incident light. These molecules can be
detected with SERS sensors by bringing them into contact with a nanostructured
metal surface, illuminated by a laser at a particular wavelength. An ideal
sensor surface should have: dense packing of metal nanostructures, commonly
gold or silver, to intensify Raman scattering; a regular arrangement to produce
repeatable signal levels; economical construction; and robustness to sustain
sensing performance over time.