Simultaneous determination of bun-creatinine as kidney function biomarkers in blood using a microfluidic paper-based analytical devices

Abstract

In this paper, we describe a Microfluidic Paper-based Analytical Devices (μPADs) for the simultaneous quantification of two important biomarkers of kidney function in blood. This paper provides a simple, disposable, portable, and inexpensive colorimetric method for the quantification of Blood Urea Nitrogen (BUN) and serum creatinine (sCRE). BUN detection is based on the Berthelot reaction, in which urea is converted to ammonium by the use of urease, ammonium ion which then reacts with a mixture of salicylate, sodium nitroprusside, and hypochlorite to yield a blue-green chromophore. sCRE detection is based on the Jaffe reaction, in which sCRE under alkaline conditions react with picrate ions forming an orange complex. The intensity of the color formed is proportional to the BUN & sCRE concentration in the sample. Various experimental parameters were optimized to achieve the best performance of the μPADs. There were no significant differences between the results obtained using the μPADs and a comparative method.