An insight into the binding behavior of graphene oxide and noble metal nanoparticles

Abstract

The binding behavior of graphene oxide and metal nanoparticles (Au, Pt, and Pd) was observed by UV–Vis spectroscopy, fluorescence spectroscopy, dynamic light scattering, and zeta potential. Hybrids with a fixed concentration of graphene oxide (GO) were prepared with increasing concentration of metal nanoparticles to observe the effect of binding on their spectroscopic properties, size, and zeta potential. An increase in the absorption spectra of GO after binding with nanoparticles and a gradual decrease in fluorescence emission intensity with increasing concentration of nanoparticles was observed, representing their effective binding. Stern–Volmer plots differentiated the quenching constants of these nanoparticles, where Au shows the lowest and Pd shows the highest quenching among these nanoparticles. The initial hybrids showed more size change as compared to hybrids with a higher concentration of nanoparticles, whereas initial hybrids have charge similar to that of GO and gradual increase in the concentration of nanoparticles bring the charge near to the respective charge of nanoparticles. To the best of our understanding, this is the first report of its kind to study the binding interactions of two different moieties by studying changes occurred in the hydrodynamic radius and zeta potential of hybrids by titration experiments, having applications in surface treatment, drug delivery, and as sensors for environmental pollutants or other classes of organic molecules, etc.

An ultrasensitive “mix-and-detect” kind of fluorescent biosensor for malaoxon detection using the AChE-ATCh-Ag-GO system

“…Additionally, the oxidation rate of graphene nanosheets plays a crucial role in controlling energy level confinement to different degrees, which ultimately affects the FE of GO. 46,51,52…”

“…Additionally, the oxidation rate of graphene nanosheets plays a crucial role in controlling energy level connement to different degrees, which ultimately affects the FE of GO. 46,51,52 As previously described, citrate ions along with the GO's oxygen moieties can assist in the prolonged stabilization of AgNPs on the GO nanosheet. Briey, the overlaying of the anions around the AgNP's surface creates strong electrostatic repulsion that allows uniform AgNPs distribution on the GO sheet.…”

An Investigation on the Effect of Extended Conjugation on the Photophysical Properties of Graphene Quantum Dot‐Porphyrin Dyads

“…[31] In our case, while plotting the concentration of GQD against F 0 /F and τ 0 /τ a nonlinearity is observed for both GQD-TPP and GQD-TNaP nanohybrids and that is a portrayal of combined static and dynamic quenching. [32,33] From the earlier reports it is concluded that there is a nonradiative electron transition that occurs from excited porphyrins to GQDs, which competes with the fluorescence of PPys. [34] This non-radiative rate constant, k nr is the comparison between the lifetime values of TPP and TNaP in the absence of GQD (τ o ) and presence of GQD (τ) as in equation 7.…”

Metallic nanoparticles and hybrids of metallic nanoparticles/graphene nanomaterials for enhanced photon harvesting and charge transport in polymer and dye sensitized solar cells

“…Hybrids of MNPs and graphene nanomaterials (GNMs) like GO, graphene quantum dots (GQDs) and reduced graphene oxide (rGO), because of their synergistic properties, find application in sensors [ 8 , 9 ], electronics [ 10 ], biomedicine [ 10 ], energy conversion [ 11 ], catalysis [ 10 ], and in removal of environmental pollutants [ 12 ], depending on the MNPs composition. For example, hybrids of GO and plasmonics have unique properties including high specific surface area, chemical and electrochemical inertness which suit them for use in biosensors and surface enhanced Raman spectroscopy (SERS) for early stage medical conditions diagnosis [ 13 ]. This review focuses on applying MNPs and hybrids of MNPs/(GNMs) in PSCs and DSSCs.…”