Recent development of eco-friendly nanocomposite carbon paste electrode for voltammetric determination of Cd(II) in real samples

Abstract

Using eco-friendly, cheap, and available adsorbents is promising for the determination of metal ions. So, this study focuses on the modification of graphite reinforcement carbon paste electrode (GRCPE) with mango seed kernel (MSK) for voltammetric determination of Cd(II). Moreover, to increase the surface area of this adsorbent, it was prepared in nanosized that formed nanoparticles of mango seed kernel (MSK-NPs). The developed nanocomposite electrode of carbon paste electrode modified with nanoparticles of mango seed kernel (MSK-NPs@GRCPE) was characterized using Fourier transform infrared (FTIR) and Scanning electron microscopy (SEM). The effect of pH, buffer solution, and supporting electrolyte as experimental conditions were optimized through differential pulse adsorptive anodic stripping voltammetric method (DPAdASV). Britton-Robinson buffer pH = 3.9 at Eacc = – 1400 mV, tacc = 30 s, pulse width = 10 ms and sampling time = 8 ms were the optimum conditions for determination of Cd(II). The LOD and LOQ of MSK-NPs@GRCPE were calculated at 5.44 × 10–9 and 1.65 × 10–8 M, respectively. Compared with bare graphite reinforcement carbon paste electrode (BGRCPE), the nanocomposite MSK-NPs@GRCPE has a lower detection limit, indicating that the presence of MSK-NPs could greatly improve the response to Cd(II). The practical applicability of the electrode was verified by the determination of Cd(II) in chocolate and white rice samples. The results show high selectivity and sensitivity for Cd(II) in real samples. Graphical abstract

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

“…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.…”

“…Several studies also reported on the use of NMs as sole electrode modifiers. 105,109,112,114,119,121,127,134,137,161,163,165,166,170,172,173,190 Table S1 in the ESI† summarizes the main findings of the research studies published in the last five years on using different NMs to determine trace heavy metals. The parameters related to the analytical performance of the modified electrodes with composites comprised of other main group modifiers are presented in Tables S2–S6 in the ESI †…”

“…In addition to the widely used electrodeposition, reduction, and hydrothermal methods, the synthesis of NPs from environmentally friendly sources ( i.e. , waste and plant extracts as well as mango seed kernels) has been reported, 23,119–122,125,127 and will be further discussed in section 7.…”

“…In the last five years, several research groups have continued to explore the inclusion of various environmentally friendly (green) modifiers in the development of new electrodes for trace metal analysis. 23,35,37,61,66,69,71–73,87,89,92,104,110,120–127,157,175,186,187,197,201–205,219,289,293,313–321 Table S6 in the ESI† summarizes the main findings of the research studies published in the last five years reporting on the use of different green modifiers for various types of electrodes employed in the determination of trace heavy metals.…”

“…A wide range of green modifiers has been employed, including biopolymers, 35,37,61,69,71–73,87,89,92,123,124,175,186,187,197,201–205 plant extracts, 23,66,104,120–122,125,127,313 natural products, 126,219,314–318 biomass, 157,289,319 and DNA. 293,320,321 It is important to emphasize that all the different green modifiers have been either added to or combined with other modifiers to achieve the desired electroanalytical performance of the newly developed electrodes through the synergistic effect.…”