Molecularly imprinted polymer capped near infrared fluorescent emitting Ag2S-functionalized-COOH quantum dots for detection of creatinine as a nanosensor with high sensitivity and selectivity

Abstract

Maintaining creatinine at high and low level is critical because it causes so many problems such as diabetic nephropathy, muscular dystrophy, renal failure, and urinary tract blocking. In this study, a high-performance near-infrared fluorescent Ag2S-functionalized-COOH quantum dots (QDs) capped with molecularly imprinted polymer (MIP) was developed (Ag2S@MIP) and used as a facile selective and sensitive detector for creatinine. Ethylene glycol dimethacrylate as cross-linker and creatinine as template molecules was used to prepare Ag2S@MIP fluorescent nanoparticles (∼42 nm) of the core-shell structure and by grafting methacrylic acid monomer on the surface of methacrylate-functionalized Ag2S QDs using suspension polymerization.The Ag2S@MIP nanoparticles were prepared and characterized by FESEM, FT-IR, DLS, TGA, XRD, and EDS. The Ag2S@MIP nanoparticles displayed a fluorescence emission band at ∼834 nm and quenched strongly upon the addition of creatinine. The adsorption of creatinine at various experimental conditions such as fluorescent emission, selectivity, adsorption/desorption processes, and reusability of Ag2S@MIP was measured. The outstanding adsorption capacity (∼492 mg/g) and the selectivity factor of Ag2S@MIP give a promising sensor for the detection and determination of creatinine in the human serum.