Abstract
This study presents an integrated microfluidic chip for non-immunologically determining the concentrations of albumin in clinical urine samples. This microchip integrates membrane-type micromixers and a fan-shaped micropump capable of simultaneously and precisely delivering assay reagents to react with 6 urine samples in one single operation. The experimental results show that the coefficient of variation in the pumping rate is 2.42%. More importantly, using this unique chip design, only 2 electromagnetic valves are required for the actuation of the micromixer and the micropump. The working range of the proposed microchip is 2-200 mg/L of albumin, which covers the range of interest for the determination of microalbuminuria. Moreover, statistical analysis show that the results obtained by the proposed microchip are in good agreement with the conventional detection method, based on immunological assays. This simple, inexpensive and microchip-based platform presents a promising alternative to conventional immunological assays for measurement of urinary albumin, and is well suited for clinical applications. © Springer Science+Business Media, LLC 2010.