Measurement of creatinine in human plasma using a functional porous polymer structure sensing motif

In this study, a new method for detecting creatinine was developed. This novel sensor comprised of two ionic liquids, poly-lactic-co-glycolic acid (PLGA) and 1-butyl-3-methylimidazolium (BMIM) chloride, in the presence of 2′,7′-dichlorofluorescein diacetate (DCFH-DA). PLGA and BMIM chloride formed a functional porous polymer structure (FPPS)-like structure. Creatinine within the FPPS rapidly hydrolyzed and released OH(−), which in turn converted DCFH-DA to DCFH, developing an intense green color or green fluorescence. The conversion of DCFH to DCF(+) resulted in swelling of FPPS and increased solubility. This DCF(+)-based sensor could detect creatinine levels with detection limit of 5 µM and also measure the creatinine in blood. This novel method could be used in diagnostic applications for monitoring individuals with renal dysfunction.