Surface enhanced Raman detection of the colon cancer biomarker cytidine by using magnetized nanoparticles of the type Fe.sub.3O.sub.4/Au/Ag

Cytidine is regarded as an early marker of colon cancer. The authors describe a surface enhanced Raman scattering (SERS) technique to detect trace levels of cytidine in urine. The Raman band at 784 cm.sup.-1 can be acquired best. Compared to earlier methods, an improvement in detection sensitivity by a factor of 6.2 x 10.sup.5 is achieved by using a magnetically induced method in which cytidine is captured in the vicinity of the SERS hot spots of the type Fe.sub.3O.sub.4/Au/Ag. Cytidine can be quantified at 1 nM levels by this method which is simple and reliable.