A noninvasive cancer detection strategy based on gold nanoparticle surface-enhanced raman spectroscopy of urinary modified nucleosides isolated by affinity chromatography

The search for tumor biomarkers in the urine for cancer diagnosis is currently a hot topic in clinical oncology, with potential for cancer screening and diagnosis. Modified nucleosides excreted through the urine are considered to be a general tumor marker for various cancer types. Herein, we explore a new method that utilizes surface-enhanced Raman scattering (SERS) spectroscopy to obtain a complete biochemical profile of urinary modified nucleosides. In our method, modified nucleosides are first isolated from urine sample utilizing the excellent separation ability of affinity chromatography; then supplemented with gold (Au) nanoparticles as substrate for SERS spectroscopy analysis. The obtained SERS spectra present rich diagnostic and fingerprinting type signatures of urinary modified nucleosides. The utility of this new method in cancer detection was evaluated by analyzing urine samples from three groups of subjects: nasopharyngeal cancer patients (n=62), esophageal cancer patients (n=55), and healthy volunteers (n=52). Partial least squares and linear discriminant analysis (PLS-DA) were used to analyze and classify the SERS spectra of urinary modified nucleosides from nasopharyngeal cancer, esophageal cancer, and the normal group, achieving diagnostic sensitivities of 95.2%, 90.9% and 98.1% and specificities of 97.2%, 98.2% and 95.7%, respectively. These results demonstrated great potential of this novel method for non-invasive and label-free cancer detection and screening.