High performance Au/Ag core/shell bipyramids for determination of thiram based on surface‐enhanced Raman scattering

Abstract

Au/Ag core/shell bipyramids were used as surface-enhanced Raman scattering (SERS) substrates to determine the thiram. The metallic substrates showed high SERS performance and are very suitable for the analytical sensors. The fabrication and characterization of the Au/Ag core/shell bipyramids were described. The influence of experimental parameters, such as the thickness of Ag shell of the bipyramids, sodium chloride concentration, and pH value on SERS of thiram was examined and optimized. Under the optimum conditions, thiram molecules were effectively adsorbed onto bipyramids and the SERS intensity is proportional to the concentration of thiram in the range of 3.3 to 400.0 ng mL -1 . The corresponding correlation coefficient of the linear equation is 0.997, which indicates that there is a good linear relationship between SERS intensity and thiram concentration. The limit of detection for thiram is 2.0 ng mL -1 . The experimental results indicate that the proposed method is a viable method for determination of thiram. Some environmental water samples were analyzed and the analytical results were satisfactory.

Surface-enhanced Raman scattering on a hierarchical structural Ag nano-crown array in different detection ways

“…39 The SERS spectra of thiram collected on the SERS substrate are shown in Fig. 6a and a plot of SERS intensity with the thiram concentration is presented in Fig.…”

Cicada wing decorated by silver nanoparticles as low-cost and active/sensitive substrates for surface-enhanced Raman scattering

“…The lowest peak at $1445 cm À1 was due to the antisymmetric n (CH 3 ) stretch. 42 Similar to the case for the R6G detection, Figure 6(b) revealed a linearly relation between the logI of the integrated signal intensities centered at 1380 cm À1 and the logC of thiram concentration. The concentration dependence necessary for the target molecule intensities provided a method for rapid and quantitative detection of R6G, thiram and other organic molecules.…”

“…6(a), the SERS spectra of thiram with different concentrations for 10 À3 $ 10 À7 M was detected, and the detection limit was as low as 10 À7 M. The highest peak was the CN stretching mode and symmetric CH 3 deformation mode at $1380 cm À1 . 11,42 The other peaks in the SERS spectra of thiram were at about 932, 1148, and 1506 cm À1 , which were attributed to the C ¼ S and CH 3 N stretching vibrations, the CN stretching vibrations and rocking CH 3 mode, respectively. The lowest peak at $1445 cm À1 was due to the antisymmetric n (CH 3 ) stretch.…”

“…41 Meanwhile, pesticide residues have been concerned as the food safety issues for the public health. 42 Among these issues, thiram (bis-(dimethyl-dithiocarbamoyl) disulfide), a nonsystemic dithiocarbamate fungicide, has been widely used to protect a variety of crops from downy mildew, blight, anthracnose, and cereal smut. 41,43 Due to the lack of environmental awareness and the excessive use of thiram, water and soil are being polluted while much of the residue remains in the surface of fruits and vegetables.…”

Low-cost Au nanoparticle-decorated cicada wing as sensitive and recyclable substrates for surface enhanced Raman scattering

“…Therefore we adopted 10 −7 M as the approximate LOD for both R6G and thiram. The highest peak (at ∼1368 cm −1 ) in the spectra was the result of CN stretching mode and symmetric CH 3 deformation mode work together [33]. The other peaks were at 936, 1138, 1434 and 1486 cm −1 , which were attributed to the C S and CH 3 N stretching vibrations, the CN stretching vibrations, the antisymmetric n(CH 3 ) stretch and rocking CH 3 mode, respectively [34,35].…”