Development of Paper-Based Sensor Coupled With Smartphone Detector for Simple Creatinine Determination

Creatinine level in urine is one of the most important indicators for kidney diseases. A routine assay for this compound is vital especially for those who suffer from kidney malfunction. However, the existing methods are mostly expensive, impractical and time consuming. Here in, we report a research on the development of sensor for creatinine analysis by using cheap materials such as paper and coupled with a smartphone as the detector leading to an inexpensive and free-instrument method. This research was done based on the Jaffe reaction in which the creatinine was reacted with picric acid in basic solution to form an orange-red creatinine-picric complex. The red-green-blue intensity of the complex, captured with a smartphone, was measured and then digitized with free-download Microsoft Visual c# 20101 Express applications, as the analytical response. This proposed method was evaluated based on its precision, accuracy, percent of recovery and limit of detection. It was found that the precision, accuracy, percent of recovery and limit of detection of this method were 5.55%, 0.74 %, 96.73 +/- 6.12 % and 8.02 ppm, respectively. It can be concluded that the paper based sensors with digital imaging approach using Microsoft Visual c# 20101 Express,with its simplicity and affordabilitycan be applied for on-site determination of creatinine level.