title: Silica-coated, Au/Ag striped nanowires for bioanalysis.
abstract: Striped metallic nanowires (NW) have been coated with a silica shell of controllable thickness (6-150 nm), and the assay performance of coated vs uncoated NW has been compared. The silica coating does not interfere with identification of the metal striping pattern and protects Ag segments from oxidation, extending the range of assay conditions under which barcoded NW can be used. Much higher and more uniform fluorescence intensities were observed for dye-labeled ssDNA bound to SiO2-coated as compared to intensities for uncoated NW. Simultaneous, multiplexed DNA hybridization assays for three pathogen-specific target sequences on SiO2-coated NW showed good discrimination of complementary from noncomplementary targets. Application of SiO2-coated NW in discrimination of single base mismatches corresponding to a mutation of the p53 gene was also demonstrated. Finally, we have shown that thiolated probe DNA resists desorption under thermocycling conditions if attached via siloxane chemistry to SiO2-coated NW, but not if it is attached via direct adsorption to bare Au/Ag NW.
authors: Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors: James A
authors: JA
authors: Sioss
authors: Rebecca L
authors: RL
authors: Stoermer
authors: Michael Y
authors: MY
authors: Sha
authors: Christine D
authors: CD
authors: Keating
mesh_terms: D020137:Base Pair Mismatch; D001483:Base Sequence; D020099:Coated Materials, Biocompatible; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D005456:Fluorescent Dyes; D006046:Gold; D006678:HIV / Q000235:genetics; D016174:Hepacivirus / Q000235:genetics; D006515:Hepatitis B virus / Q000235:genetics; D046529:Microscopy, Electron, Transmission; D036103:Nanotechnology; D053770:Nanowires / Q000737:chemistry / Q000648:ultrastructure; D015345:Oligonucleotide Probes / Q000235:genetics; D012822:Silicon Dioxide; D012834:Silver
chemical_list: D020099:Coated Materials, Biocompatible; D004279:DNA, Viral; D005456:Fluorescent Dyes; D015345:Oligonucleotide Probes; D012834:Silver; D006046:Gold; D012822:Silicon Dioxide