Abstract

This work aimed to report the paper-based analytical devices (PADs) developed to determine the albumin-to-creatinine ratio (ACR) using the colorimetric method as a simple detection system. The detection of albumin (ALB) was based on the dye-binding reaction by immobilizing Bromothymol Blue (BTB) onto the PADs. The color change from yellow to blue was identified when ALB reacted with BTB. Creatinine (CRE) detection was carried out according to the Jaffe reaction by reacting CRE with alkaline picrate, which was immobilized onto the PADs, resulting in the color change from yellow to orange CRE–picrate complex. The intensity of the color formed is proportional to the concentration of ALB and CRE. The proposed method was successfully applied to detect ACR in synthetic urine samples with accuracy in the range of 77%–93% and relative standard deviations < 5%. The detection limits for ALB and CRE were 2.4 and 5.3 mg dl−1, respectively. This device provides an inexpensive, simple, fast, disposable, and affordable tool for possible early detection of kidney damage because of nephropathy.

Key words: albumin, creatinine, kidney, nephropathy, paper-based analytical devices.