Silver Nanoparticle Decorated Reduced Graphene Oxide (rGO) Nanosheet: A Platform for SERS Based Low-Level Detection of Uranyl Ion

Abstract

Herein, a simple wet-chemical pathway has been demonstrated for the synthesis of silver nanoparticle conjugated reduced graphene oxide nanosheets where dimethylformamide (DMF) is judiciously employed as an efficient reducing agent. Altogether, DMF reduces both silver nitrate (AgNO3) and graphene oxide (GO) in the reaction mixture. Additionally, the presence of polyvinylpyrolidone (PVP) assists the nanophasic growth and homogeneous distribution of the plasmonic nanoparticle Ag(0). Reduction of graphene oxide and the presence of aggregated Ag NPs on reduced graphene oxide (rGO) nanosheets are confirmed from various spectroscopic techniques. Finally, the composite material has been exploited as an intriguing platform for surface enhanced Raman scattering (SERS) based selective detection of uranyl (UO2(2+)) ion. The limit of detection has been achieved to be as low as 10 nM. Here the normal Raman spectral (NRS) band of uranyl acetate (UAc) at 838 cm(-1) shifts to 714 and 730 cm(-1) as SERS bands for pH 5.0 and 12.0, respectively. This distinguished Raman shift of the symmetric stretching mode for UO2(2+) ion is indicative of pronounced charge transfer (CT) effect. This CT effect even supports the higher sensitivity of the protocol toward UO2(2+) over other tested oxo-ions. It is anticipated that rGO nanosheets furnish a convenient compartment to favor the interaction between Ag NPs and UO2(2+) ion through proximity induced adsorption even at low concentration.

Simultaneous Synthesis and Assembly of Silver Nanoparticles to Three-Demensional Superstructures for Sensitive Surface-Enhanced Raman Spectroscopy Detection

“…25 Furthermore, the difference between the doublets of Ag 3d electronic state of 6.0 eV suggests the presence of Ag 0 in the fabricated Ag superstructures, consistent with the XRD analysis. 25 A strong absorption peak at around 429 nm can be observed in the absorption spectrum, as displayed in Figure 3b, which is assigned to the surface plasmon resonance of Ag superstructures. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 geometric features with 3D heterogeneous architectures can be generated by adjusting the adsorption time of [Ag(NH 3 ) 2 ] + .…”

Oxides in silver–graphene nanocomposites: electrochemical signatures and electrocatalytic implications

“…11 The synthesis of graphene/GO immobilised silver, gold, platinum and palladium nanoparticles has been reported by several research groups. [12][13][14][15][16] Among metals, silver nanoparticles deposited onto graphene/rGO have been found to exhibit excellent electrocatalytic and electrosensing properties. 17,18 Needless to mention, the electrocatalytic and electrosensing properties of nanodimensional silver composite materials are strongly sensitive to the shape, size and oxidation state of the silver.…”

Apoptosis inducing ability of silver decorated highly reduced graphene oxide nanocomposites in A549 lung cancer

“…28 Additionally, trace amounts of toxic-reducing agents present on the surface of these materials could seriously affect the potential properties of highly reduced graphene oxide (HRG) and have undesirable effects on its biological applications. 16 Whereas, the green synthesis of graphene-based materials involves biocompatible ingredients under physiological conditions of temperature and pressure.…”