The presence of relatively high concentrations of nitrite (NO2−) in exhaled breath may be indicative of the presence of inflammatory processes within the airways, and so measuring it may be an effective way of performing early detection of the onset of the symptoms of asthma and other respiratory conditions. Devices that are able to measure nitrite are bulky and impractical for everyday use, but Rutgers University scientists have now developed a graphene-based sensor for measuring the concentration of nitrite in exhaled breath that they believe will result in a new approach to monitoring and managing asthma and similar conditions, helping patients to avoid attacks before they even start.
The nitrite sensor is based on graphene, a flat sheet of carbon atoms, and can be made small and resilient enough for patients to take along with them throughout their day. If it reaches the clinical stage, the sensing technology would be used to regularly take readings of nitrite in breath, potentially helping to decide when and how much of an anti-inflammatory to take.
Some details about the new nitrite sensor from the study abstract in journal Microsystems and Nanoengineering:
We utilized the unique properties of reduced graphene oxide (rGO); specifically, the material is resilient to corrosion while exhibiting rapid electron transfer with electrolytes, thus allowing for highly sensitive electrochemical detection with minimal fouling. Our rGO sensor was housed in an electrochemical cell fabricated from polydimethyl siloxane (PDMS), which was necessary to analyze small EBC sample volumes. The sensor is capable of detecting nitrite at a low over-potential of 0.7 V with respect to an Ag/AgCl reference electrode.
Study in journal Microsystems and Nanoengineering: Toward point-of-care management of chronic respiratory conditions: Electrochemical sensing of nitrite content in exhaled breath condensate using reduced graphene oxide…
(hat tip: Graphene-Info)