NANOBIOSENSOR FOR RAPID DETECTION OF CREATININE CRYSTALS PRESENT IN URINE

Abstract

Creatine is synthesized primarily in the liver and kidneys from amino acids and is phosphorylated to phosphocreatine, which serves as an energy source in muscle. Creatine is non-enzymatically degraded to creatinine at a constant rate and excreted in the urine. Its formation mainly depends on the muscle mass. Changes in creatine and creatinine levels may be related to various diseases (e.g. kidney disease, rhabdomyolysis etc.). Several methods are used to determine creatinine, such as for example the Jaffe method using the reaction of creatinine with picric acid in an alkaline medium, forming a red-orange complex or the enzymatic Trinder reaction. In some cases, crystals or larger aggregates are present in the urine. Primary diagnosis of such crystals is focused on microscopic evidence of the presence of the structure and may be confirmed by FTIR. The three enzymes, creatinase, creatininase and sarcosine oxidase can also be used for qualitative assessment of creatinine. The aim of this work was to design a SPION nanobiosensor for qualitative proof of the presence of creatinine in a sample. The methodology uses the highly sensitive Red Amplex fluorophore. Absorbance dependence on creatinine concentration read off at the wavelength of 572 nm was linear over a total range of 0 -1000 μM.