Point-of-care assay platform for uric acid, urea, and triglycerides with a microfluidic paper device (μPAD) controlled by stimulus-sensitive valves

A microfluidic biosensor paper-based analytical device, or mu PAD, was developed as a point-of-care assay platform for the simultaneous determination of three clinically important markers: uric acid, urea, and triglycerides. To achieve a simultaneous determination, thermosensitive valves based on N-isopropylacrylamide polymers controlled the flow of fluid in the mu PAD.The evaluation of the analytical characteristics of the mu PAD was done using a photographic camera at room temperature.The detection limits were 4.5.10- 5, 2.5.10-3, and 1.5.10-3 mg mL-1, for uric acid, urea, and triglycerides, respectively, and the precision expressed as relative standard deviation (% RSD) 3.2, 1.2, and 1.6%. The obtained mu PAD devices were validated with real human plasma samples, demonstrating high accuracy and precision. Multiple analyte point-of-care tests such as those developed here have excellent characteristics, being easy to manufacture, cost-effective, easy to use, and highly sensitive.