Colorimetric determination of albumin to creatinine ratio using paper-based analytical devices for rapid detection of kidney disfunction

Diabetic nephropathy is a common complication of diabetes, which can lead to chronic renal failure in patients. Chronic kidney disease (CKD) is a condition characterized by abnormalities and loss of kidney function. Early detection of nephropathy can prevent the progression of this disease to CKD. In this work, both albumin (ALB) and creatinine (CRE) were used as biomarkers for detecting albumin to creatinine ratio (ACR) using paper-based analytical devices (PADs) by applying the alkaline picrate and bromocresol purple (BCP) reagents as the reagent solutions. ALB detections were performed by a dye-binding method using BCP reagent resulted in the color change from yellow to purple, while CRE detection was based on the Jaffe reaction using picric acid in an alkaline solution resulted in the color change from yellow to orange. The color changes were photographed by a digital camera and the pictures' color intensity (RGB) were evaluated using ImageJ. The ACR in artificial samples was measured using the calibration curve constructing by plotting logarithmic of ACR (mg g-1) against the Δintensity ALB/CRE ratio. The accuracy of ACR determination in artificial samples were found in the range of 75.70 - 99.98%, whereas their standard deviations were in the range of 0.01 - 0.02, showing relatively good accuracy and high precision of the proposed method. The detection limits (LOD) for albumin (ALB) and creatinine (CRE) were 8.2?mg.dL-1 and 5.1?mg.dL-1, respectively. The fast, cheap, and easy-to-use method for ACR detection could be attributed to the proposed method. Additionally, it has relatively good accuracy and high precision, and it can potentially be used as an alternative technique for early detecting or screening kidney disease.