A nanotech sensor that turns molecular fingerprints into bar codes

Infrared spectroscopy is the benchmark method for detecting and analyzing organic compounds. But it requires complicated procedures and large, expensive instruments, making device miniaturization challenging and hindering its use for some industrial and medical applications and for data collection out in the field, such as for measuring pollutant concentrations. Furthermore, it is fundamentally limited by low sensitivities and therefore requires large sample amounts. However, scientists at EPFL's School of Engineering and at Australian National University (ANU) have developed a compact and sensitive nanophotonic system that can identify a molecule's absorption characteristics without using conventional spectrometry. Their system consists of an engineered surface covered with hundreds of tiny sensors called metapixels, which can generate a distinct bar code for every molecule that the surface comes into contact with. These bar codes can be massively analyzed and classified using advanced pattern recognition and sorting technology such as artificial neural networks. This research -- which sits at the crossroads of physics, nanotechnology and big data -- has been published in Science.