Ionophore-based optical sensor for urine creatinine determination

Creatinine is a metabolite present in urine, and its concentration is used to diagnose and monitor kidney performance. For that reason, the development of new sensors to analyze this metabolite and obtain accurate results in a short period of time is necessary. An optical disposable sensor for monitoring creatinine levels in urine is described. The system, based on a new aryl-substituted calix[4]pyrrole synthetic receptor, has an unusual coextraction scheme. Due to the low pKa values of creatininium (pKa 4.8), a careful selection of a lipophilic pH indicator that works in acid medium is required. The sensor components were optimized, and the new sensor displays a good response time to creatinine (approximately 3 min) over a wide dynamic range (from 1 × 10−5 to 1 × 10−2 M). Moreover, the optical selectivity coefficients obtained for creatinine over common cations present in urine meet the requirements for real sample measurements. With a good sensor-to-sensor reproducibility (RSD, 5.1−6.9% in the middle of the range), this method provides a simple, quick, cost-effective, and selective alternative to the conventional methodology based on Jaffé’s reaction
FQM-118
MINECO (CTQ2016-78754-C2-1-R)
Spanish Ministry of Economy and Competitiveness and European Regional Development Fund (ERDF) CTQ2016-77128-R
MINECO (CTQ2017-84319-P)
Severo Ochoa Excellence Accreditation 2014-2018 SEV-2013-0319
FEDER funds (Project CTQ2017- 84319-P)
CERCA Programme/Generalitat de Catalunya and AGAUR (2017 SGR 1123)