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 μPAD, 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 μPAD. The evaluation of the analytical characteristics of the μPAD was done using a photographic camera at room temperature. The detection limits were 4.5·10, 2.5·10, and 1.5·10 mg mL, 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 μPAD 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.