ACS Photon. 1, 17–26 (2014)

Credit: © 2014 ACS

A smart phone's image sensor is capable of detecting signals required for Raman spectroscopy, according to researchers in Turkey. Sencer Ayas and co-workers from Bilkent University integrated a smart phone into a confocal Raman microscope set-up that had been modified to enable the phone's camera to record wide-field Raman images. This modification involved placing a collimator and a dispersive optical element in front of the camera. The team was able to record Raman spectra from ethanol and silicon, the latter being excited by a focused beam from a green laser (wavelength, 532 nm; power, 10 mW). The scheme was also applied to nanostructured silver substrates, which are compatible with surface enhanced Raman spectroscopy. In this case, the researchers observed blink events on the phone's camera that were associated with a single-molecule sensitivity. This achievement was possible as a result of a large enhancement in the Raman signal on the order of 106 to 107 by the plasmonic substrates. The researchers say that the spectrum of the blink events can be observed at a rate of 30 frames per second.