Functionalized graphene oxide-based carbon paste electrode for potentiometric detection of copper ion(ii)

Abstract

For the first time, a novel copper ion(II) carbon paste electrode (CPE) based on high-density carboxyl functionalized graphene oxide (GO) is reported. A new hybrid material, 2-amino-5-mercapto-1,3,4thiiodiazole grafted onto nanoscale graphene oxide (AMT-g-NGO), was introduced as a neutral carrier. The electrode exhibits an excellent Nernstian response to copper ion(II) ranging from 1.0 Â 10 À7 M to 1.0 Â 10 À1 M with a slope of 26.2 mV dec À1 . Meanwhile, the proposed electrode shows fairly good selectivity and a long life time (2 months). Moreover, the excellent performance on low detection limit (4.0 Â 10 À8 M), wide applicable pH range (3.0-7.0) and fast response time (15 s), reveal the superiority of the electrode. The response mechanism of the electrode was investigated using AC impedance technique and UV-vis spectroscopy. The sensor can be used as indicator electrode for potentiometric titration of Cu 2+ ion with EDTA and successfully applied to the determination of Cu 2+ ion in different real samples.

Reduced graphene oxide–silver nanoparticle nanocomposite: a potential anticancer nanotherapy

“…Furthermore, the absorption peak at approximately 1,270 cm −1 is attributed to the C-OH bond, and the new absorption band at 1,570 cm −1 is attributed to the skeletal vibration of the graphene sheets. 71,80 These results clearly demonstrate that GO was successfully exfoliated and reduced to graphene and that strong interactions may exist between AgNPs and the remaining surface hydroxyl groups. 81 seM analysis of gO, rgO, and rgO-ag nanocomposite Figure 4 shows the SEM images of GO (Figure 4a), rGO (Figure 4b), and rGO-Ag (Figure 4c).…”

“…The UV-Vis spectrum of rGO exhibits a characteristic band at 261 nm, indicating the restoration of the extensive conjugated sp 2 carbon network. 10,57,[69][70][71] A new peak at 410 nm is observed after the deposition of AgNPs on the rGO surface; the band at 410 nm in the absorption spectrum of the rGO-Ag nanocomposite is attributed to surface plasmons and indicates the presence of AgNPs. 64,69,71,72 The disappearance of the characteristic peaks of rGO and the emergence of a new band originating from AgNPs clearly indicate the simultaneous reduction of both rGO and AgNO 3 and the formation of the rGO-Ag composite.…”

“…71,86,87 This technique provided additional evidence of the reducing ability of TAPE for GO and AgNO 3 . As shown in Figure 6, in the Raman spectrum of GO, the G band is broadened and shifted to 1,599 cm −1 while a broadened D band at 1,347 cm −1 also appears ( Figure 6A).…”

Carbon Paste Electrodes

“…Signal improvement for oxidation of guanosine [155] Host molecules Formation of host-guest complexes Cyclodextrins detn. of phenols and polycyclic aromatic amines [156][157][158] Crown ethers detn.…”

“…-Graphene and graphene oxide. This planar nanocarbon [95,154] together with its oxidized form [155] can also be employed as special modifiers with adsorptive and catalytic properties. Host-guest coupling agents: This supramolecular affinity can be exploited for immobilization and accumulation, and the most popular examples are cyclodextrins [156][157][158], crown ethers [145,159], and calixarenes [160].…”