Determination of glucose and uric acid with bienzyme colorimetry on microfluidic paper-based analysis devices

In this work, we first employ a drying method combining with the bienzyme colorimetric detection of glucose and uric acid on microfluidic paper-based analysis devices (mu PADs). The channels of 3D mu PADs are also designed by us to get better results. The color results are recorded by both Gel Documentation systems and a common camera. By using Gel Documentation systems the limits of detection (LOD) of glucose and uric acid are 3.81 x 10(-5) M and 4.31 x 10(-5) M, respectively one order of magnitude lower than that of the reported methods on mu PADs. By using a common camera, the limits of detection (LOD) of glucose and uric acid are 2.13 x 10(-4) M and 2.87 x 10(-4) M, respectively. Furthermore, the effects of detection conditions have been investigated and discussed comprehensively. Human serum samples are detected with satisfactory results, which are comparable with the clinical testing results. A low-cost, simple and rapid colorimetric method for the simultaneous detection of glucose and uric acid on the mu PADs has been developed with enhanced sensitivity. (C) 2012 Elsevier B.V. All rights reserved.