When it comes to testing for cancer, environmental pollution and food contaminants, traditional sensors can help. The challenges are that they often are bulky, expensive, non-intuitive and complicated. Now, one team reports in ACS Sensors that portable pressure-based detectors coupled with smartphone software could provide a simpler, more affordable alternative while still maintaining sensitivity.
Current disease and contamination sensors require expensive readout equipment or trained personnel. Yuehe Lin, Yong Tang and colleagues propose a new detection system based on pressure changes. For example, when a disease biomarker is present, it 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 team 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.