title: Fabrication of large-scale gold nanoplate films as highly active SERS substrates for label-free DNA detection.
abstract: We introduce a simple but robust label-free method to detect DNA based on large-scale gold nanoplate (GNP) films with tunable localized surface plasmon resonance (LSPR) and highly surface-enhanced Raman scattering (SERS) activity. The common probe molecule, Neil Blue A sulfate (NBA) is used for testing the SERS activity of the GNP films at very low concentrations. It is found that the SERS properties are highly dependent on the edge lengths of gold nanoplate and gold nanoplate density in the films. Multiple-layer GNP films which are constructed by gold nanoplate with an edge length of 134±6nm have the density of 916±40GNPsGNPs/spot. It shows the highest signal intensity with SERS enhancement factor (EF) as high as 5.4×10(7) and also has excellent stability, reproducibility and repeatability. The optimized SERS-active substrate with the largest enhancement ability could be used to detect double-strand DNA without a dye label, and the detection limit is down to 10(-6)mg/mL.
authors.affiliation: State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, PR China.
authors.forename: Liyan
authors.initials: L
authors.lastname: Bi
authors.forename: Yanying
authors.initials: Y
authors.lastname: Rao
authors.forename: Qin
authors.initials: Q
authors.lastname: Tao
authors.forename: Jian
authors.initials: J
authors.lastname: Dong
authors.forename: Ting
authors.initials: T
authors.lastname: Su
authors.forename: Fangjing
authors.initials: F
authors.lastname: Liu
authors.forename: Weiping
authors.initials: W
authors.lastname: Qian
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation; D004247:DNA / Q000032:analysis* / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation*; D013194:Staining and Labeling; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D008567:Membranes, Artificial; D006046:Gold; D004247:DNA