Asthma, which causes inflammation of the airway and obstructs airflow, affects about 300 million people worldwide. Symptoms include coughing, wheezing, shortness of breath, and chest tightness. Other serious lung ailments include chronic obstructive pulmonary disease (COPD), which encompasses emphysema and chronic bronchitis.
Today’s non-invasive methods for diagnosing and monitoring asthma are limited in characterizing the nature and degree of airway inflammation, and require costly, bulky equipment that patients cannot easily keep with them. The methods include spirometry, which measures breathing capacity, and testing for exhaled nitric oxide, an indicator of airway inflammation. There’s an urgent need for improved, minimally invasive methods for the molecular diagnosis and monitoring of asthma. Measuring biomarkers in exhaled breath condensate — tiny liquid droplets discharged during breathing — can contribute to understanding asthma at the molecular level, and lead to targeted treatment and better disease management.
A graphene-based sensor was developed that could lead to earlier detection of asthma attacks, and improve the management of asthma and other respiratory diseases, preventing hospitalizations and deaths. The sensor paves the way for the development of devices — possibly resembling fitness trackers — that people could wear and then know when and at what dosage to take their medication.
The miniaturized electrochemical sensor accurately measures nitrite in exhaled breath condensate using reduced graphene oxide, which resists corrosion, has superior electrical properties, and is very accurate in detecting biomarkers. The system could also be used in a physician’s office and emergency departments to monitor the effectiveness of various antiinflammatory drugs to optimize treatment.
Simply looking at coughing, wheezing, and other outward symptoms, diagnosis accuracy is often poor; the idea of monitoring biomarkers continuously can result in a paradigm shift. The ability to perform label-free quantification of nitrite content in exhaled breath condensate in a single step without any sample pre-treatment resolves a key bottleneck to enabling portable asthma management.
The next step is to develop a portable, wearable system that could be commercially available within five years. The researchers also envision expanding the number of inflammation biomarkers a device could detect and measure.