Surface Enhanced Raman Spectroscopy-Based Method for Leukemia Biomarker Detection Using Magnetic Core @ Gold Shell Nanoparticles

We present here the surface-enhanced Raman spectroscopic (SERS)-based detection of the Wilm's tumor gene (WT1) sequence using dye-labeled reporter oligonucleotide and magnetic core @ gold shell nanoparticles. Thiolated single-stranded DNA (ssDNA) complementers of the WT1 sequence were used to functionalize the gold shell with capture oligonucleotides in a facile and fast two-step method. The signal amplification performance of the core @ shell colloidal SERS substrate was tested using malachite green as label dye. The Raman signal enhancing efficacy of the magnetic core @ gold shell nanomaterial was compared with the efficacy of spherical gold particles produced using the conventional citrate reduction method. The core @ shell particles were found to be superior both regarding robustness in SERS and facile separation in a heterogeneous reaction system. The core @ shell particles functionalized with target specific oligonucleotide were able to capture the WT1 target and worked as Raman signal amplifiers in our assay system. The good physicochemical characteristics of these particles and the sensitivity observed in SERS experiments allow us to expect good performance in the further development steps of a novel, fast and reliable spectroscopic method for WT1 detection in minimal residual disease patients. © 2014 Springer Science+Business Media New York.