Graphene oxide and shape-controlled silver nanoparticle hybrids for ultrasensitive single-particle surface-enhanced Raman scattering (SERS) sensing

Abstract

Graphene oxide (GO) is an emerging material for surface-enhanced Raman scattering (SERS) due to its strong chemical enhancement. Studying the SERS performance of plasmonic nanoparticle/GO hybrid materials at the single particle level is crucial for direct probing of the chemical effect of GO on plasmonic nanoparticles. In this work, we integrate GO and shape-controlled Ag nanoparticles to create hybrid nanomaterials, and the chemical enhancement arising from GO is investigated using single-particle SERS measurements. Ag nanoparticle@GO hybrid nanostructures are prepared by assembling Ag nanoparticles, including spheres, cubes and octahedra with GO sheets. The SERS behaviors of the hybrid nanostructures are characterized, and 2-3 times enhanced SERS intensities are detected from the Ag nanoparticle@GO hybrid nanostructures as compared to pure Ag nanoparticles. Furthermore, we probe the mechanism of SERS enhancement in the hybrid nanostructures by changing the surface coverage of GO on Ag octahedra, by using reduced GO in place of GO as well as by using probe molecules of different electronegativities. This hybrid system is an excellent candidate for single-particle SERS sensors. Sub-nanomolar levels of aromatic molecules are detected using a single Ag/GO hybrid nanomaterial. This as-prepared GO and shape-controlled Ag nanoparticle hybrid is capable of serving as a high performance SERS platform, providing new opportunities for efficient chemical and biological sensing applications.

High-resolution nanotransfer printing applicable to diverse surfaces via interface-targeted adhesion switching

“…8), which is comparable with the best reported detection level [55][56][57][58] . It should be noted that the signal intensity obtained from the commercial SERS substrate at the same concentration was negligibly small.…”

Facile synthesis of gold nanoparticles-graphene oxide films and their excellent surface-enhanced Raman scattering activity

“…The other bands of 1380, 1510 and 1650 cm -1 are assigned to the C-C stretching modes. The vibrational band presented at 241 cm -1 indicated that a chemisorptive bond has been formed (Au-N) between Au NPs and R6G via the ethylamino group [20]. It is clearly seen that R6G solid have high fluorescence and low Raman intensity (in Fig.…”

“…Both of the films have prominent D and G bands. The G mode and D mode correspond to the firstorder scattering of E 2g phonon of C sp 2 atoms and a breathing mode of k-point phonons of A 1g symmetry, respectively [20]. The intensity ratios of D/G (I D /I G ) are Facile synthesis of gold nanoparticles-graphene oxide films and their excellent surface-… approximate 0.99 for GO and 0.97 for Au NPs-GO film, which are consistent with the references.…”

Organic–inorganic nanohybrids for fluorescence, photoacoustic and Raman bioimaging

“…SERS has been well developed and becomes one of the most popular and powerful methods for the enhancement of Raman scattering [42]. The principle of this approach is the use of nanoscale roughened metal surface to adsorb molecules, which leads to a considerable enhancement of Raman signals.…”