Point-of-care testing of four chronic disease biomarkers in blood based on a low cost and low system complexity microfluidic chip with integrated oxygen-sensitive membrane

Point-of-care testing (POCT) of multiple chronic disease biomarkers is crucial for effective prevention and management of chronic diseases. Here, we developed a sensing platform based on microfluidics chip and oxygen-sensitive membrane (OSM), which utilized enzymatic oxygen consumption and OSM based signal conversion for portable detection of glucose, total cholesterol, uric acid, and triglyceride in blood. Their detection limits were 0.04 mM, 0.07 mM, 0.01 mM, and 0.05 mM, respectively, meeting clinical requirements. To avoid the reliance on laboratory equipment, a handheld mini centrifuge modified from a toy fan was developed for plasma separation and a smartphone was used for signal acquisition. In addition, signal conversion based OSM simplified reagent composition. Dry storage of reagents on the chip simplified operations and improved the stability of reagents. For chronic disease biomarkers in blood, the results obtained by our chips were consistent with commercial kits. We believe that this sensitive, low-cost, equipment-free sensing platform has a significant potential in self-management of chronic diseases.