Development of microfluidic paper-based analytical device for determination of creatinine in urine samples

Abstract

The simple, low-cost and portable microfluidic paper-based analytical devices (µPADs) for colorimetric determination of creatinine in urine samples were developed. The methodology was based on Jaffé reaction between the creatinine and picric acid in alkaline medium generating a colorimetric creatinine-alkaline picrate complex. The product exhibits an orange color which is clearly visible on µPADs. The color intensity of the complex which is indicative of the concentration of creatinine is then quantitatively determined using ImageJ software. Various experimental parameters were optimized, i.e., concentration of picric acid, concentration of sodium hydroxide, and reaction time, and the best analytical performance was achieved with 0.04 M picric acid, 2 M sodium hydroxide, and 25 minutes of reaction time. Under the optimum conditions, a wide linear range was obtained in the range of 0.2 – 1 mM with a limit of detection (LOD) and a limit of quantitation (LOQ) of 0.08 mM and 0.26 mM, respectively. Moreover, this method provided a selective determination of creatinine and showed a good reproducibility with a precision of 2.85, 1.10 and 1.64 %RSD for the detection of creatinine at 0.2, 0.6 and 1 mM, respectively. The accuracy of the proposed method was not significantly different from the standard Jaffé method by a paired t-test at 95% confidence interval. Finally, the developed devices were successfully applied for the determination of creatinine in urine samples with %recoveries in the range of 91.06-102.86%.