A nanoreceptor-based electronic nose system (NaNose) is being developed, at the Laboratory of the co-PI (Prof. Haick, Faculty of Chemical Engineering, Technion, Haifa, Israel), capable of detecting traces of VOCs in concentrations of single parts-per-billion (1µg/l). Paired with a computerized system able to analyze large amounts of data from hundreds of molecules, detected simultaneously by an array of 20 or more receptors, this system surpasses the other "electronic nose" devices in terms of sensitivity and efficiency. Contrary to costly and slow GC-MS systems, an ideal nanomaterial-based sensor for breath testing should be sensitive at very low concentrations of volatile organic compounds, even in the presence of environmental or physiological confounding factors. It should also respond rapidly and proportionately to small changes in concentration and provide a consistent output that is specific to a given compound. When not in contact with the compounds in question, the sensor should quickly return to its baseline state, or be simple and inexpensive enough to be disposable.