1. Ultrasensitive and stable SERS detection by defect engineering constructed Ag@Ga-doped ZnO core-shell nanoparticles.
- Author
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Wu, Haoran, Wang, Jingjing, Yang, Qiong, Qin, Shaoxiong, Li, Zixiu, Zhang, Yang, Pan, Jiaqi, and Li, Chaorong
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HAZARDOUS substances , *ZINC oxide , *NANOPARTICLES , *METHODS engineering , *SURFACE defects , *PESTICIDES - Abstract
Ag@Ga-doped ZnO core-shell nanoparticles show excellent SERS sensitivity, stability and repeatability, which is attributed to its rich surface defects, plasmon- and photo-induced charge-transfer effect by its unique core-shell structure. [Display omitted] • Ag@Ga-doped ZnO core-shell nanoparticles were successfully prepared by simple solvothermal method and defect engineering. • Such SERS substrates exhibits high sensitivity, stability and repeatability. • The detection limit of the substrate for pesticide thiram can reach 10−9 M, which is far lower than the national standard. • The Ag@2.6%Ga-ZnO CSNPs can complete catalytic degradation of organic dye molecule R6G within 40 min. • SERS enhanced mechanism was discussed in detail. There has been increasing interest in evolution of semiconductor-based SERS-active substrates to achieve ultrasensitive detection of trace analyte molecules. This work presents a simple solvothermal method and further defect engineering technology to obtain Ag@Ga-doped ZnO core-shell nanoparticles (Ag@n%Ga-ZnO CSNPs), which have both local electromagnetic enhancement from Ag-core and efficient charge transfer enhancement due to the plasmon and photo-induced electrons and numerous deficiency sites after Ga-doping, for achieving ultrahigh detection sensitivity, stability and repeatability. Specifically, the unique Ag@2.6%Ga-ZnO CSNPs exhibited good linearity in the range from 10−6 to 10−12 M for the typical dye analyte rhodamine 6G (R6G), and the limit of detection could be down to 10−12 M. The Raman signal intensity of the Ga-doped core-shell structure was stable after 60 days of storage at room temperature. Moreover, the as-prepared Ag@2.6%Ga-ZnO CSNPs shows excellent signal repeatability as SERS substrate, and the relative standard deviation (RSD) is calculated to be about 9.71%. To illustrate the usefulness for detection of hazardous substance, we showed that such substrate can detect a pesticide, thiram, at a concentration as low as 10−9 M, which is far lower than the national standard. In addition, due to the construction of the core-shell structure and the introduction of Ga-doping, the photoelectric properties of the material have also been greatly improved. Under the irradiation of xenon lamp, the Ag@2.6%Ga-ZnO CSNPs can complete catalytic degradation of organic dye molecule R6G and pesticide molecule thiram within 40 to 50 min. This study demonstrated that the Ag@Ga-doped ZnO core-shell nanoparticles could serve as an effective and versatile SERS platform for reproducible, fast and in-field detection of organic analytes at trace levels. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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