Spectrophotometric Detection of the Amino Acid Sarcosine Using its Hydrolysis by Sarcosine Oxidase

Abstract

Prostate cancer is the most common malignant tumor in men, whose incidence significantly differs geographically and increases with age. For rapid diagnostics, new tumor markers with higher prognostic relevance are still being sought. A very promising candidate molecule is the amino acid sarcosine. The aim of this work was to design a highly sensitive photometric detection system for the sarcosine determination. An original, yet unpublished, methodology for determining the amino acid sarcosine using Trinder's reaction has been proposed. Absorbance dependence on sarcosine concentration at 546 nm is linear over a total range of 0–1000 μM (r ≥ 0.99) with limit of detection (LOD) of 6 μM and limit of quantification (LOQ) of 20 μM. The suggested procedure allows to analyze the content of sarcosine in real urine specimens at micromolar concentrations.