A new method for selective determination of creatinine using smartphone-based digital image

A new and simple analytical method for creatinine determination in human serum and urine samples was developed. The method is based on the reaction of creatinine and N-(1-naphthyl) ethylenediamine (NED) in acidic conditions. A colorimetric reaction based on NED was tested for measuring creatinine concentration with high sensitivity by the microfluidic paper-based analytical device (mu PAD). The intensity of the color was checked by observation or by capturing an image and quantification of the signal with ImageJ 1.46r software or color picker app. Under the optimal conditions, the microfluidic device was enabled to determine creatinine in the 0.03-0.50 mM analytical range with a 0.022 mM limit of detection. The strategy proposed in this study could be performed in many clinical laboratories.

Automated summary

A new and simple analytical method for creatinine determination in human serum and urine samples was developed using a microfluidic paper-based analytical device. The method is based on the reaction of creatinine and N-(1-naphthyl) ethylenediamine in acidic conditions. The microfluidic device enables the determination of creatinine in a wide range of concentrations with high sensitivity.