Thread based microfluidic platform for urinary creatinine analysis

Abstract

Creatinine level in urine is a key factor to monitor kidney performance. The use of an alternative microfluidic platform based on cellulose substrates is an interesting option to integrate sample treatment, creatinine re- cognition by ionophore extraction chemistry and quantification by color measurement through consumer electronics imaging devices. The inclusion of ionophore extraction chemistry based on aryl-substituted calix[4] pyrrole synthetic receptor on 8.7 mm long cotton thread permit the sample treatment, optical recognition of creatinine and their quantification by smartphone running app in unfiltered urine samples diluted 1:100 ratio. The device shows a short response time, 30 s, to creatinine over a wide dynamic range (from 1.6× 10 6 to 5 10–2 M) with precision between 2.9–4.3%. The low interference level of representative species in urine is studied and justified by density functional theory (DFT) calculations.