Nanotech Sensor Turns Molecular Fingerprints Into Barcodes

Benchmark for detecting and analyzing organic compound is considered to be infrared spectroscopy, requiring complicated procedures and expensive instruments. Miniaturizing devices has been challenging as a result for some industrial, data collecting, and medical applications. A compact and sensitive nanophotonic system has been developed by EPFL researchers which can identify molecule absorption characteristics without the need of traditional spectrometry.

The highly sensitive system combines big data, physics, and nanotechnology consisting of an engineered surface covered in tiny metapixel sensors that can generate a distinct barcode for every molecule the surface comes into contact with. Codes can be analyzed and classified using advanced pattern recognition and sorting technology such as artificial neural networks.

Chemical bonds in organic molecules have specific orientation and vibrational mode, as each molecule has a set of characteristic energy levels commonly located in the mid-infrared range, each type absorbs light at different frequencies giving each one a unique signature. Infrared spectroscopy can be a costly process to detect whether a molecule is present in samples being seen in light rays absorption signature frequency.

The EPFL system can be miniaturized and made portable, the process uses nanostructures to capture light on the nanoscale to provide high detection levels for sample on the surface in nanometric scale, bridging the sensitivity and size gap. The system’s nanostructures are grouped into metapixels that resonate at a different frequencies. Molecules that come into contact with the system surface the way the molecules absorb light changes behavior of all the metapixels it touches.  Metapixels are arranged in such a way the different vibrational frequencies are mapped into different areas on the surface, creating a pixelated map of light absorption that can be translated into molecular barcodes, without using a spectrometer.

The system is compatible with CMOS technology and has already been used to detect pesticides, organic compounds, and polymers. The EPFL system has various potential applications, and could be used for portable medical testing such as generating barcodes for each biomarker found within blood samples. Artificial intelligence could be used with the technology to create and process databanks of molecular barcodes ranging from DNA to polymers to protein or pesticides providing a tool to quickly and accurately spot miniscule compound amounts in complex samples.