Portable pressure-based detectors coupled with smartphone software could provide a simpler, more affordable 
The barometer-based biosensor detects a broad range of targets. (Source: American Chemical Society)alternative to traditional bulky, expensive environmental or medical sensors while still maintaining sensitivity.
While current disease and contamination sensors require expensive readout equipment or trained personnel, the new detection system is based simply on pressure changes. For example, the presence of a disease biomarker causes a chain reaction in the device that results in oxygen being released and pressure building. The pressure changes are measured by a portable barometer, and smartphone software provides an easy readout of the results.
To show the versatility of the pressure sensor, the researchers from Washington State University and Jinan University (Guangzhou, China) tested a variety of applications. Prototypes could detect carcinoembryonic antigen, a protein present in high levels in patients with colon or rectal cancer; ractopamine, which is an animal-feed additive banned in many countries; and thrombin, a cardiovascular disease marker. In addition, a mercury-ion sensor was developed for environmental pollution monitoring. The researchers say that because the results are immediately available with a smartphone, the method could enable real-time monitoring of environmental pollution, disease outbreaks and food safety.
