Lab-on-a-chip for measuring uric acid in biological fluids

This paper describes a lab-on-a-chip for measuring uric acid in serum, plasma or urine. The lab-on-a-chip is composed by two dies: one is fabricated in polystyrene and contains the microchannels and the other is fabricated through a CMOS process and contains the photodetector and readout electronics. The uric acid concentration is measured by using a mixture of 14 μl of infinity uric acid reagent with 0.25 μl of sample. The achieved sensitivity is 0.33 mg/dl (±0.6% of human being urine values), with a 1 mm lightpath. Using an optical absorption method, a maximum peak at wavelength λ = 494 nm, is detected.