Low cost, ultra-thin films of reduced graphene oxide–Ag nanoparticle hybrids as SERS based excellent dye sensors

Single sea urchin–MoO3 nanostructure for surface enhanced Raman spectroscopy of dyes

“…R6G is one of the highly uorescent dyes and an active analyte for SERS studies due to its large Raman scattering cross-section 43 and molecular resonance effect when irradiated with visible light. [40][41][42][43] Fig . 6a displays the baseline corrected SERS spectra of 1 mM concentration of R6G on a glass substrate, and MoO 3 sea urchin and h-MoO 3 modied substrates.…”

“…The bands around 1504, 1536 and 1644 cm À1 are assigned to C-C stretching vibrations. [41][42][43][44] In order to analyze the SERS effect, the intensities of 612 cm À1 and 1358 cm À1 peaks of 1 mM R6G over various MoO 3 nanostructures are compared in Fig. 6b.…”

“…Simultaneously, electrons also get excited from the HOMO to the LUMO level in the dye molecules especially with 532 nm laser excitation, which can be transferred to the conduction band of MoO 3 levels. 41,[46][47][48] In the case of MoO 3 sea urchins, the effect gets accentuated by the surface defects and oxygen vacancies present in the sea urchin tips promoting the adsorbate-adsorbent interactions. In addition to the charge transfer mechanism, contribution from local dipole moment due to the surface OH species of sea urchins can also result in the enhancement.…”

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

“…(Guerrini & Graham, 2012) Graphene, which is an ideal two-dimensional monolayer sheet of hexagonal carbon atoms, has been reported that it could be used as a substrate for enhancement of Raman signals of absorbed molecules due to CM. (Kavitha, Bramhaiah, John, & Ramachandran, 2015) However, several issues limit the practical applications of graphene in SERS, such as the aggregation in aqueous solution caused by the strong p-p stacking interaction between graphene sheets, and the chemical inertia originated from the defect-free structure. (Neto, Guinea, Peres, Novoselov, Geim, & K., 2007) Compared to graphene, graphene oxide(GO), an exfoliation of graphite oxide, has great dispersibility in aqueous solution and many reactive sites for decorating organic or inorganic species due to the fact that it contains hydroxyl and epoxy groups in the plane and carboxyl groups at the edge.…”

Improved surface-enhanced Raman and catalytic activities of reduced graphene oxide–osmium hybrid nano thin films

“…Hence, synthesis of high performance and compatible nanohybrid thin films with desired properties via simple chemical methods is gaining significance in recent times. We have been using reduced graphene oxide (rGO)-based metal and metal oxide nanoparticles in the form of thin films prepared via liquid/liquid interface for applications involving surface-enhanced Raman spectroscopy (SERS)-based molecular detection [ 1 , 2 ]. We have shown that the charge transfer and fluorescence quenching by rGO aids in improved enhancement factors and detection of dyes.…”