), which permits unrestricted use, distribution, and reproduction in any medium, offered
), which permits unrestricted use, distribution, and reproduction in any medium, offered the original operate is effectively credited.Zhou et al. Nanoscale Study Letters 2014, 9:302 nanoscalereslett.com/content/9/1/Page two ofor by simply heating or evaporating FCC-Ag nanowires or nanoparticles [20,21]. Different metal nanostructures containing HCP structures with distinct morphologies which includes Ag belts [22], prisms [23], needles [24], rices [25], Au square sheets [26], and tadpoles [27] have already been researched. As to crystal structure composition, except the researches [18,26] in which the composition are exclusively HCP, HCP coexists with FCC in the majority of the aforementioned reports. Ag nanowires with diameters about 30 nm prepared by electrochemical deposition are discovered to have the highest concentration in the total of HCP to FCC nanowires [17]. Even so, you will discover few reports about regulating the ratio of HCP to FCC in solution-phase synthesis and additional researching the reaction parameters affecting it, neither the inherent development mechanism. In this paper, the size and morphology from the flowerlike silver nanostructures and additional the ratio of HCP to FCC phase is usually manipulated by varying the level of catalyzing agent added towards the option. Contemplating there exists an optimal point where HCP phase could be the richest with each other together with the indispensable element on the nature of stabilizing agents, the proposed growth mechanisms is corroborated. Using these flower-like Ag nanostructures as SERS substrates, the Raman signal of Rhodamine 6G (R6G) or 4-aminothiophenol (4-ATP) with concentration 10-7 M is usually recognized resulting from numerous hot spots.Methods Aqueous remedy (37 CH2O, 28 NH3H2O, and 40 C2H4O) was bought from Sinopharm Chemical Reagent Co. Ltd (Shanghai, China). Polyvinylpyrrolidone (PVP, k30), AgNO3, sodium sulfate (SS), and sodium dodecyl sulfate (SDS) with analytical pure grade had been supplied by the same corporation. R6G (98 ) and 4-ATP (97 ) was purchased from Sigma-Aldrich Organization (Shanghai, China). Within a α2β1 list standard synthetic procedure, 200 mL 0.25 mM AgNO3 aqueous solution at 45 was sequentially added to 0.1 mL aqueous answer of 37 CH2O and 0.four mL 28 NH3H2O. It can be worth mentioning that NH3H2O ought to be injected rapidly. Just after 1 min, 10 mL 10 (w/w) PVP aqueous remedy was mixed into the option so as to stabilize the silver nanostructures. After 4 more min, the product was collected by centrifugation at six,000 r min-1. The volume of NH3H2O varied from 200 to 800 L, and for simplification, the silver nanostructures samples are denoted as P200, P400, P600, and P800, respectively. To confirm the directing function of formic acid, which can be the oxidation solution of CH2O, SS or SDS instead of PVP was injected in similar concentration and the silver nanostructures samples are denoted as SS400 and SDS 400, respectively.The morphology of the samples was characterized by a scanning electron microscope (SEM, Hitachi S-4800). The phase constitution in the samples was examined by X-ray diffraction (XRD) working with an X’Pert PRO X-ray diffractometer equipped with all the graphite monochromatized Cu K radiation. The extinction spectra from the samples have been measured on Ocean Optics spectrophotometer with an optical path of 10 mm over the array of 200 to 1,100 nm. The PI3KC2β list integration time is 6 ms. To employ flower-like Ag NPs as SERS substrate, firstly, the flower-like particles were deposited onto a square silicon wafer with side length of ten mm, and then immerse.