Colorimetric Detection of Creatinine on an Electromechanical Mixing Platform

Abstract

We present an electromechanical mixing platform integrated with a smartphone for colorimetric detection of creatinine using an enzymatic reaction between horseradish peroxidase (HRP) and 3,3',5,5'-Tetramethylbenzidine (TMB). On the developed platform, the color resulting from the reaction between HRP and TMB in a reservoir of a poly(methyl methacrylate) (PMMA) chip is measured using a smartphone camera. With mixing, diluted creatine solutions can be detected in 1 min that can reduce long waiting times of creatinine detection due to enzymatic reactions. Furthermore, smartphone-based colorimetric detection reduces the cost of analysis by eliminating costly equipment for spectrometric measurements without affecting the sensitivity of analysis. We, therefore, think that the presented platform integrated with a smartphone could be used for automatic measurement of creatinine level in the sample by allowing low-cost and rapid analysis, and this would be particularly beneficial for monitoring of chronic kidney disease (CKD) at the point-of-care setting.