In a major step towards a Fitbit-like wearable device to monitor and manage asthma, researchers have created a graphene-based sensor that can detect inflammation in lungs.

The researchers believe that the sensor could lead to earlier detection of looming asthma attacks and improve the management of asthma and other respiratory diseases, preventing hospitalisation and death."Our vision is to develop a device that someone with asthma or another respiratory disease can wear around their neck or on their wrist and blow into it periodically to predict the onset of an asthma attack or other problems," said Mehdi Javanmard, Assistant Professor at Rutgers University-New Brunswick in New Jersey, US."It advances the field of personalised and precision medicine," Javanmard said. Asthma, which causes inflammation of the airway and obstructs air flow, affects about 300 million people worldwide. The symptoms include coughing, wheezing, shortness of breath and chest tightness.

Today's non-invasive methods for diagnosing and monitoring asthma are limited in characterising the nature and degree of airway inflammation, and require costly, bulky equipment that patients cannot easily keep with them.There is an urgent need for improved, minimally invasive methods for the molecular diagnosis and monitoring of asthma, the study published online in the journal Microsystems & Nanoengineering said.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.

The researchers' miniaturised electrochemical sensor accurately measures nitrite in exhaled breath condensate using reduced graphene oxide.Reduced graphene oxide resists corrosion, has superior electrical properties and is very accurate in detecting biomarkers."Nitrite level in breath condensate is a promising biomarker for inflammation in the respiratory tract. Having a rapid, easy method to measure it can help an asthmatic determine if air pollutants are affecting them so they can better manage use of medication and physical activity," said Clifford Weisel, study co-author and Professor at Rutgers University.

"Just looking at coughing, wheezing and other outward symptoms, diagnosis accuracy is often poor, so that's why this idea of monitoring biomarkers continuously can result in a paradigm shift," Javanmard said.The next step is to develop a portable, wearable system, which could be commercially available within five years, he added. The researchers said they also envision expanding the number of inflammation biomarkers a device could detect and measure.