Microfluidic paper-based platform for whole blood creatinine detection

An integrated platform consisting of a three-dimensional (3-D) microfluidic paper-based analytical device (mu PAD) and a portable detection system is proposed for the determination of human whole blood creatinine. In the proposed detection method, the reaction region of the 3-D mu PAD is implanted with picric acid and NaOH reagent and allowed to dry. Whole human blood is then dripped onto the inlet region of the chip and the blood plasma diffuses through the separation channel into the reaction zone under the effects of capillary action. The mu PAD is heated at a temperature of 37 degrees C for 5 min to induce a Jaffe reaction between the creatinine in the blood plasma and the reagent. Finally, the creatinine concentration is detected using a colorimetric method. The validity of the proposed approach is demonstrated using control samples with creatinine concentrations ranging from 0.19 to 7.64 mg/dL. The detection results obtained for 40 real-world human serum creatinine samples and 30 real-world whole blood samples are shown to be in excellent agreement with those obtained using a conventional macroscale assay technique. Overall, the results show that the proposed platform provides a compact, low-cost and reliable approach for whole blood creatinine concentration detection.