Diagnosis of kidney conditions using low-cost paper diagnostics

Abstract

Kidneys are important body organ, which prevent waste buildup in human body, maintain stable electrolyte levels and regulate blood pressure and blood pH. In recent years, complications related to decreased kidney function and kidney failure have become a worldwide public health problem. A gradual reduction in kidney function can lead to Hyperuricemia (high uric acid), formation of kidney stones, kidney tumor and other chronic kidney diseases and can cause kidney failure. However, some of these adverse effects can be prevented or delayed by early detection and subsequent treatment. Paper diagnostic devices (PADs) can play a vital role in low-cost and rapid diagnosis of kidney condition, resulting in early detection of kidney complications. Paper diagnostics are paper and cellulose based analytical devices capable of qualitative or quantitative detection of biomarkers (molecules, genes, antibodies, antigens etc.) from biofluids (blood, urine etc.). In this study, different biomarkers for kidney diagnosis and detection techniques for specified biomarkers were analyzed, and low-cost paper diagnostic devices for qualitative and quantitative detection of important kidney biomarkers (for example: uric acid and creatinine) from biofluids (for example: urine) were developed. To detect, uric acid and creatinine concentration in human urine samples, colorimetric reactions were used. The reactions produce color signals on paper surface, and these signals can be analyzed and quantified using image analysis software. The temperature effect on color signal formation was measured, and use of urinary uric acid to creatinine ratio for diagnosis of other diseases was explored. Laboratory trials on three adult male samples were performed to assess the validity of the proposed techniques. Finally, codes were developed for image analysis using MATLAB application which could be potentially used in telemedicine using cell phone and computers.