Nanoparticles with Raman Spectroscopic Fingerprints for DNA and RNA Detection

Abstract

Multiplexed detection of oligonucleotide targets has been performed with gold nanoparticle probes labeled with oligonucleotides and Raman-active dyes. The gold nanoparticles facilitate the formation of a silver coating that acts as a surface-enhanced Raman scattering promoter for the dye-labeled particles that have been captured by target molecules and an underlying chip in microarray format. The strategy provides the high-sensitivity and high-selectivity attributes of gray-scale scanometric detection but adds multiplexing and ratioing capabilities because a very large number of probes can be designed based on the concept of using a Raman tag as a narrow-band spectroscopic fingerprint. Six dissimilar DNA targets with six Raman-labeled nanoparticle probes were distinguished, as well as two RNA targets with single nucleotide polymorphisms. The current unoptimized detection limit of this method is 20 femtomolar.

Engineering the synthesis of silica–gold nano-urchin particles using continuous synthesis

“…5,6 Gold nanoparticles have been synthesized by a variety of approaches for diverse applications in catalysis, bio-imaging, drug delivery and photovoltaics. Their surface plasmon resonance (SPR) and surface enhanced Raman scattering (SERS) properties have been of particular interest for photothermal therapy and molecular sensing, respectively [7][8][9][10][11][12][13][14][15] . SERS active structures have been fabricated by complex with top-down methods, 4,12,16,17 but wet-chemical synthesis of gold nanoparticles offer potential advantages in simple, high yield, and limited scalable synthesis.…”

Intracellular Distribution of TiO2−DNA Oligonucleotide Nanoconjugates Directed to Nucleolus and Mitochondria Indicates Sequence Specificity

“…Nanoconjugates with oligonucleotide components exist in several guises-with nanoparticles made of different materials 5,12,13,15,16,22 . Functions of these nanoconjugates are varied as well-from imaging 17,18,21 to nucleic acid, DNA 5 or RNA 13 hybridization and/or cleavage, with or without aid from the cellular enzymatic machinery.…”

Detection of Sequence-Specific Protein-DNA Interactions via Surface Enhanced Resonance Raman Scattering

“…Double-stranded oligonucleotides C (oligo-C) of lengths 15 to 39 base pairs containing the protein binding site of interest were designed to generate appropriate spacing for protein access into the final assemblies, with 12 base pair single-stranded overhangs on each end that are complementary to surface-bound 22 base pair oligonucleotides A or B (oligo-A or oligo-B, DNA sequences in Supporting Information). Gold NPs diameter of ∼13 nm were prepared by citrate reduction of gold aurate, 11 and the resultant citrate shell was displaced by thiolmodified oligo-A or oligo-B 10 . Conjugates were determined to have 183 ( 20 oligonucleotides per particle (Supporting Information).…”

“…Nanoparticles of this size have previously been used as seeds for silver plating and multiplexed detection by SERRS. 11 Upon annealing of the single-stranded overhangs, the three components condense into assemblies. 10 Variations of assemblies were formed with oligo-C containing the GCGC recognition site of M.HhaI, 12 the TATA-box recognition site of TATA-binding protein (TBP), 13 or with a central thymine base coupled to a biotin for streptavidin.…”