title: Polymer nanopillar-gold arrays as surface-enhanced Raman spectroscopy substrate for the simultaneous detection of multiple genes.
abstract: In our study, 2D nanopillar arrays with plasmonic crystal properties are optimized for surface-enhanced Raman spectroscopy (SERS) application and tested in a biochemical assay for the simultaneous detection of multiple genetic leukemia biomarkers. The special fabrication process combining soft lithography and plasma deposition techniques allows tailoring of the structural and chemical parameters of the crystal surfaces. In this way, it has been possible to tune the plasmonic resonance spectral position close to the excitation wavelength of the monochromatic laser light source in order to maximize the enhancing properties of the substrate. Samples are characterized by scanning electron microscopy and reflectance measurements and tested for SERS activity using malachite green. Besides, as the developed substrate had been prepared on a simple glass slide, SERS detection from the support side is also demonstrated. The optimized substrate is functionalized with thiol-modified capture oligonucleotides, and concentration-dependent signal of the target nucleotide is detected in a sandwich assay with labeled gold nanoparticles. Gold nanoparticles functionalized with different DNA and various Raman reporters are applied in a microarray-based assay recognizing a disease biomarker (Wilms tumor gene) and housekeeping gene expressions in the same time on spatially separated microspots. The multiplexing performance of the SERS-based bioassay is illustrated by distinguishing Raman dyes based on their complex spectral fingerprints.
authors.affiliation: Fondazione Don Carlo Gnocchi ONLUS , Piazzale Morandi 6, 20121 Milan, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Picciolini
authors.forename: Dora
authors.initials: D
authors.lastname: Mehn
authors.forename: Carlo
authors.initials: C
authors.lastname: Morasso
authors.forename: Renzo
authors.initials: R
authors.lastname: Vanna
authors.forename: Marzia
authors.initials: M
authors.lastname: Bedoni
authors.forename: Paola
authors.initials: P
authors.lastname: Pellacani
authors.forename: Gerardo
authors.initials: G
authors.lastname: Marchesini
authors.forename: Andrea
authors.initials: A
authors.lastname: Valsesia
authors.forename: Davide
authors.initials: D
authors.lastname: Prosperi
authors.forename: Cristina
authors.initials: C
authors.lastname: Tresoldi
authors.forename: Fabio
authors.initials: F
authors.lastname: Ciceri
authors.forename: Furio
authors.initials: F
authors.lastname: Gramatica
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D006046:Gold / Q000737:chemistry*; D007938:Leukemia / Q000235:genetics / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D014408:Biomarkers, Tumor; D011108:Polymers; D006046:Gold
keywords: DNA microarray; SERS; leukemia; multiplex; nanopillar; plasmonic