title: Label-free surface-enhanced Raman spectroscopy detection of DNA with single-base sensitivity.
abstract: Direct, label-free detection of unmodified DNA is a great challenge for DNA analyses. Surface-enhanced Raman spectroscopy (SERS) is a promising tool for DNA analyses by providing intrinsic chemical information with a high sensitivity. To address the irreproducibility in SERS analysis that hampers reliable DNA detection, we used iodide-modified Ag nanoparticles to obtain highly reproducible SERS signals of single- and double-strand DNA in aqueous solutions close to physiological conditions. The phosphate backbone signal was used as an internal standard to calibrate the absolute signal of each base for a more reliable determination of the DNA structure, which has not been achieved before. Clear identification of DNA with single-base sensitivity and the observation of a hybridization event have been demonstrated.
authors.forename: Li-Jia
authors.initials: LJ
authors.lastname: Xu
authors.forename: Zhi-Chao
authors.initials: ZC
authors.lastname: Lei
authors.forename: Jiuxing
authors.initials: J
authors.lastname: Li
authors.forename: Cheng
authors.initials: C
authors.lastname: Zong
authors.forename: Chaoyong James
authors.initials: CJ
authors.lastname: Yang
authors.forename: Bin
authors.initials: B
authors.lastname: Ren
mesh_terms: D004247:DNA / Q000032:analysis* / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D013499:Surface Properties
chemical_list: D004247:DNA