Microfluidic optoelectronic sensor for salivary diagnostics of stomach cancer.

We present a microfluidic optoelectronic sensor for saliva diagnostics with a potential application for non-invasive early diagnosis of stomach cancer. Stomach cancer is the second most common cause of cancer-related deaths in the world. The primary identified cause is infection by a gram-negative bacterium Helicobacter pylori . These bacteria secrete the enzyme urease that converts urea into carbon dioxide (CO 2 ) and ammonia (NH 3 ), leading to their elevated levels in breath and body fluids. The proposed optoelectronic sensor will detect clinically relevant levels of CO 2 and NH 3 in saliva that can potentially be used for early diagnosis of stomach cancer. The sensor is composed of the embedded in a microfluidic device array of microwells filled with ion-exchange polymer microbeads doped with various organic dyes. The optical response of this unique highly diverse sensor is monitored over a broad spectrum, which provides a platform for cross-reactive sensitivity and allows detection of CO 2 and NH 3 in saliva at ppm levels. [ABSTRACT FROM AUTHOR]