Preparation of SERS-active substrates based on graphene oxide/silver nanocomposites for rapid zdetection of l-Theanine

Abstract

A kind of graphene oxide/silver (GO/Ag) nanocomposites with high Surface enhanced Raman scattering (SERS) activity were fabricated via a facile and green liquid phase reduction method. The synthesized materials were characterized in detail using various microscopic and spectroscopic techniques. In this method, the GO sheets worked as a holder which makes silver nanoparticles (AgNPs) aggregate to a particular morphology, and under a suitable dosage of silver ions, well-dispersed AgNPs on the surface of GO were obtained, which could generate more "hot spots" of SERS. Moreover, SERS technique based on the obtained GO/Ag nanocomposites was used as an effective way to detect l-Theanine. The detection limit was estimated to be as low as 10(-7)M, and a multivariate linear regression model for the concentration of l-Theanine was established. The optimal fitting equation is Y=5.6765+0.0307X1458-0.0267X1251.

Bi5FeTi3O15 nanofibers/graphene nanocomposites as an effective counter electrode for dye-sensitized solar cells

“…Although 2D band is characteristic peak for graphene in Raman spectrum, in some literatures for graphene composited with inorganics, no 2D band was observed [31–33]. Moreover, in the references 15 and 31, the Raman measurement of graphene shows that the intensity of D-band ( I D ) is relatively higher than that of G-band ( I G ), while I G is larger than that of I D for the graphene oxide [34].

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Multibranch Gold Nanoparticles as Surface-Enhanced Raman Spectroscopy Substrates for Rapid and Sensitive Analysis of Fipronil in Eggs

“…The peaks at 610, 770, and 1178 cm −1 attribute to C-C-C ring in-plane vibration, C-H out-of-plane vibration, and C-H in-plane vibration, respectively [39]. The peaks at 1305, 1357, 1504, and 1643 cm −1 are corresponding to in-plane xanthene ring breathing, xanthene ring stretching with aromatic C-C stretching, in-plane C-H bending, and xanthene ring stretching with in-plane N-H vibration, respectively [40]. These peaks could still be observed even when the R6G solution was diluted to 1 × 10 −8 mol/L ( Figure S3A).…”

Au-Decorated Dragonfly Wing Bioscaffold Arrays as Flexible Surface-Enhanced Raman Scattering (SERS) Substrate for Simultaneous Determination of Pesticide Residues

“…Among all the reported techniques, SERS has been proven to be a powerful fingerprinting technique, allowing for simple, rapid, high-sensitive and non-destructive identification of trace molecules [8][9][10]. By integrating all these advantages, SERS technique can partly remedy the disadvantages of other approaches and has been one of the best candidates applied in public security [11], biomedical science [12], environmental monitoring [13 ] and food analysis [14]. It is widely accepted that the amplification of the Raman signals can be confirmed as the result of two comprehensive effects: electromagnetic enhancement (EM) and chemical enhancement (CM) mechanism.…”