In-situ fabrication of reduced graphene oxide/leucomethylene blue/platinum nanoparticles modified electrode for voltammetric determination of trace Fe(II) in seawater

Abstract

In this work, the modified electrode based on composites of reduced graphene oxide/leucomethylene blue/platinum nanoparticles (rGO/LMB/PtNPs) was fabricated in-situ via an electron relay effect. Cationic dye of methylene blue (MB) was absorbed on the surface of graphene oxide (GO) with through π-π bond interactions. Then PtCl 6 2− ions were self-assembled on the surface of the composites of GO/MB through Coulomb interactions. Using NaBH 4 as the reducing agent, PtNPs were formed and GO was reduced to rGO. With the aid of PtNPs, MB was catalytically degraded to LMB and a rGO/LMB/PtNPs modified electrode was successfully prepared in situ. Due to the excellent electrochemical properties of rGO and the well-established assistant reductant of MB, as well as the catalytic amplifying effect of PtNPs, this as prepared rGO/LMB/PtNPs modified electrode showed excellent properties for the voltammetric determination of Fe(II) with the linear range of 0.01 to 2 μM and a detection limit of 3 nM. This modified electrode was successfully applied to detect the content of Fe(II) in seawater.

Recent advances in the modification of electrodes for trace metal analysis: a review

“…In addition to the above-mentioned properties, carbon-based NMs are easy to apply, low cost, and abundant materials which can be further functionalized and serve as hosts for other compounds/ materials (mainly NPs). 191,192 These materials are mostly used either in combination with other modifiers, 24,30,34,47,54,56,57,59,64,67,70,75,85,86,88,107,113,115,129,147,149,160,162 or functionalized with other compounds. 146,148,158,159,167 In general, organic functionalization (i.e., oxygen and amino functionalization) and doping (mainly with nitrogen, boron, sulphur, and phosphorus) are the two main strategies used to improve the catalytic activity and increase active sites (affecting in this manner the electron-transfer process) and the hydrophilic nature of the carbon NMs.…”

“…32,98,101,142,148,154,158 However, the use of CNTs also faces challenges related to their synthesis (i.e., cost and specific route) as well as the need for binders to improve their mechanical stability. 196 Metals (i.e., Ag, Au, Bi, Pd, Pt, Pb, and Sn), [23][24][25]56,57 27,31,67,96,100,103,109,112,118,122,124,130,131,133,[135][136][137]188,197,198 are the most commonly used NPs in the modification of the electrodes. In addition, clinoptilolite (a naturally occurring zeolite containing Si and Al) NPs were ion exchanged in a Fe(II) solution, and the modified CPE obtained was used in the determination of Sn 2+ .…”

“…Five main types of NMs, i.e. , graphene, graphene oxide (GO) and reduced graphene oxide (rGO), 22–92 NPs, 23–25,27,31,56,57,59,64,67,70,83,86,87,93–138 single and multiwalled carbon nanotubes (SWCNTs and MWCNTs), 32,83,89,98,99,101,113,129,133,139–162 nanosheets, 34,85,107,111,139,162–166 and nanofibers, 167–169 have been employed in the modification of the electrodes used in the determination of heavy metals. Nanocubes, nanoflakes, nanospheres, and nanodiamonds 75,170–175 are among the other types of NMs used in the modification of the electrodes.…”

“…In addition to the above-mentioned properties, carbon-based NMs are easy to apply, low cost, and abundant materials which can be further functionalized and serve as hosts for other compounds/materials (mainly NPs). 191,192 These materials are mostly used either in combination with other modifiers, 24,30,34,47,54,56,57,59,64,67,70,75,85,86,88,107,113,115,129,147,149,160,162 or functionalized with other compounds. 146,148,158,159,167…”

A novel lipid droplets‐targeting fluorescent probe based on dicyanisophorone and carbazole for Cu2+ and its application

“…At present common metal ion monitoring methods include ion exchange resin method, [15] electrochemical detection method, [16,17] atomic absorption spectrometry, [18] quantum dot detection method, [19] etc. These methods cannot be widely used in biological and environmental Cu 2+ detection due to their disadvantages of being vulnerable to interference, poor stability, and low sensitivity.…”