title: UV-vis spectroscopy and dynamic light scattering study of gold nanorods aggregation.
abstract: Gold nanorods (AuNRs) were used as spectroscopic sensing elements to detect specific DNA sequences with a single-base mismatch sensitivity. The assay was based on the observation that the stabilizing repulsive forces between CTA(+)-coated AuNRs can be removed by citrate ions, which causes aggregation among AuNRs; whereas nucleic acids of different structures[ i.e., peptide nucleic acid (PNA), single-stranded DNA (ssDNA), PNA-DNA complex, and double-stranded DNA (dsDNA)] can retard the aggregation. Moreover, the dsDNA PNA-DNA duplexes provide larger retardation than that by unhybridized ssDNA and PNA probe. This assay can differentiate single-base mismatched targets with base substitution at different locations (center and end) with AuNRs of a larger aspect ratio. Besides ultraviolet-visable spectroscopy measurement of particle assembly-induced plasmonic coupling that in turn provides a spectroscopic detection of the specific DNA, dynamic light scattering and transmission electron microscope (TEM) were used to measure smaller degree of aggregation that can reveal sodium citrate- and dsDNA-AuNRs interactions in fine detail.
authors.affiliation: Institute of Materials Research and Engineering, Agency for Science, Technology, and Research, Singapore 117602, Singapore.
authors.forename: Roejarek
authors.initials: R
authors.lastname: Kanjanawarut
authors.forename: Bo
authors.initials: B
authors.lastname: Yuan
authors.forename: Su
authors.initials: S
authors.lastname: XiaoDi
mesh_terms: D020137:Base Pair Mismatch; D002951:Citrates / Q000737:chemistry; D004247:DNA / Q000032:analysis* / Q000138:chemical synthesis; D004277:DNA, Single-Stranded / Q000032:analysis* / Q000138:chemical synthesis; D006046:Gold / Q000737:chemistry*; D008027:Light; D043942:Nanotubes / Q000737:chemistry*; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization / Q000379:methods*; D020135:Peptide Nucleic Acids / Q000032:analysis* / Q000138:chemical synthesis; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D000077559:Sodium Citrate; D013057:Spectrum Analysis
chemical_list: D002951:Citrates; D004277:DNA, Single-Stranded; D020135:Peptide Nucleic Acids; D000077559:Sodium Citrate; D006046:Gold; D004247:DNA
references.citation: Langmuir. 2009 Jan 6;25(1):317-25
references.pmid: 19067523
references.citation: J Phys Chem B. 2006 Sep 21;110(37):18243-53
references.pmid: 16970442
references.citation: Chem Soc Rev. 2006 Nov;35(11):1084-94
references.pmid: 17057837
references.citation: J Colloid Interface Sci. 1998 Nov 1;207(1):150-158
references.pmid: 9778402
references.citation: Chem Commun (Camb). 2007 Mar 14;(10):1080-2
references.pmid: 17325812
references.citation: Mol Cancer Ther. 2004 Mar;3(3):223-32
references.pmid: 15026542
references.citation: Langmuir. 2007 Dec 4;23(25):12777-81
references.pmid: 17973504
references.citation: Lung Cancer (Auckl). 2011 Dec 29;3:1-14
references.pmid: 28210120
references.citation: Biointerphases. 2010 Sep;5(3):FA98-104
references.pmid: 21171720
references.citation: Anal Chem. 2008 Nov 15;80(22):8424-30
references.pmid: 18937420
references.citation: Toxicol Sci. 2008 Feb;101(2):239-53
references.pmid: 17872897
references.citation: Appl Environ Microbiol. 2002 Jan;68(1):235-44
references.pmid: 11772632
references.citation: Chem Rev. 2008 Feb;108(2):494-521
references.pmid: 18229956
references.citation: Nanotechnology. 2008 Sep 3;19(35):355501
references.pmid: 21828850
references.citation: J Am Chem Soc. 2005 May 11;127(18):6516-7
references.pmid: 15869256
references.citation: Biophys J. 2001 Aug;81(2):1133-43
references.pmid: 11463654
references.citation: Chembiochem. 2008 Oct 13;9(15):2363-71
references.pmid: 18821551