Ied from 200 to 800 L, and for simplification, the silver nanostructures samples are denoted as P200, P400, P600, and P800, respectively. To verify the directing function of formic acid, which is the oxidation item of CH2O, SS or SDS in place of PVP was injected in comparable concentration plus 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 with 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 of your samples have been measured on Ocean Optics spectrophotometer with an optical path of 10 mm over the range of 200 to 1,100 nm. The integration time is 6 ms. To employ flower-like Ag NPs as SERS substrate, firstly, the flower-like particles had been deposited onto a square silicon wafer with side length of ten mm, then immersed in 10-7 M ethanol answer of R6G or 4-ATP for 6 h. Bare silicon wafers had been also immersed in 10-2 M R6G or 4-ATP option for comparison. Soon after thoroughly rinsed with ethanol and drying by nitrogen, they had been subjected to Raman characterization. The data were obtained by deciding on six unique spots on the sample to average. The SERS spectra were recorded using a Bruker SENTERRA confocal Raman spectrometer coupled to a microscope with a ?20 objective (N.A. = 0.4) within a backscattering configuration. The 532-nm wavelength was applied using a holographic notch filter according to a grating of 1,200 lines mm-1 and spectral resolution of three cm-1. The Raman signals had been collected on a thermoelectrically cooled (-60 ) CCD detector by way of 50 ?1,000 m ?2 slit-type apertures. SERS data was collected with laser energy of 2 mW, a laser spot size of about two m, and integration time of 2 s. The Raman band of a silicon wafer at 520 cm-1 was utilized to calibrate the spectrometer.Benefits and discussion The SEM pictures of the flower-like Ag nanostructures with distinctive amounts of TLR7 Inhibitor Synonyms catalyzing agent NH3?H2O are shown in Figure 1. All the flower-like Ag nanostructures consisting of a silver core and several rod-like tips protruding out are abundant with higher curvature surface which include guidelines and sharp edges compared to the very MAO-A Inhibitor custom synthesis branched nanostructures in preceding reports [28,29]. There is a trend that the constituent rods develop into smaller in each longitudinal dimension (from about 1 m to dozens of nanometers) and diameter (from 150 nm to significantly less than 50 nm) as the amount of catalyzing agent NH3?H2O increases. Meanwhile, the rods become abundant; consequently, the junctions or gaps involving two or much more closely spaced rods turn to be wealthy. One intriguing point deserving to become described is the fact that there is a turning point in which a variety of types of rods with unique length and diameters coexist when the amount of NH3?H2O is 600 L (Sample P600) as shown in Figure 1C . In solution-phase synthesis of hugely branched noble metal nanostructures, the reaction rate along with the finalZhou et al. Nanoscale Research Letters 2014, 9:302 nanoscalereslett/content/9/1/Page three ofFigure 1 SEM photos with the flower-like Ag nanostructures. SEM pictures from the flower-like Ag nanostructures prepared with PVP and distinct amounts of catalyzing agent NH3?H2O: (A) 200 L, (B) 400 L, (C) 600 L, and (D) 800 L.morphology could be manipulated by the concentration in the precursor [30], the reaction time [9], the trace amount.
