Novel Bifunctional Electrocatalyst for ORR Activity and Methyl Parathion Detection Based on Reduced Graphene Oxide/Palladium Tetraphenylporphyrin Nanocomposite

We introduce a facile, eco-friendly reduced graphene oxide/palladium tetraphenylporphyrin (RGO/Pd–TPP) nanocomposite for oxygen reduction reaction (ORR) and environmental pollutant detection. The catalytic properties of RGO/Pd–TPP toward ORR and methyl parathion (MP) reduction showed excellent performance due to the synergism between RGO and Pd–TPP. The other properties of RGO/Pd–TPP nanocomposite were characterized by various microscopic and spectroscopic techniques. The as-prepared RGO/Pd–TPP electrocatalyst was further fabricated on electrode to study the ORR activity and MP sensing. The RGO/Pd–TPP modified electrode shows higher current density and less methanol tolerance than the Pt/C electrode, which revealed that the proposed material can be used as an excellent alternative to commercial Pt/C electrode. In addition, the electrocatalytic reduction of MP on RGO/Pd–TPP/GCE was briefly investigated and achieved a good analytical performance with excellent linear range (0.1–125 μM), low detection limit (7.4 nM), and higher sensitivity (4.1084 μA μM^–1 cm^–2). Besides, the modified electrode has successfully applied for the determination of MP insecticide in various water and food samples. Therefore, the finding of RGO/Pd–TPP nanocomposite can be regarded as an effective catalyst to enhance the electrocatalytic activity toward ORR and MP reduction

Innovative Strategy Based on a Novel Carbon-Black−β-Cyclodextrin Nanocomposite for the Simultaneous Determination of the Anticancer Drug Flutamide and the Environmental Pollutant 4‑Nitrophenol

In the present work, a noncovalent and eco-friendly approach was proposed to prepare a carbon-black/β-cyclodextrin (CB/β-CD) nanocomposite. CB/β-CD-nanocomposite-modified screen-printed carbon electrodes were applied for the simultaneous determination of the anticancer drug flutamide (Flut) and the environmental pollutant 4-nitrophenol (4-NP). The electrochemical performance of the proposed sensor relied on the conductivity of CB, the different binding strengths of the guests (Flut and 4-NP) to the host (β-CD), and the different reduction potentials of the nitroaromatic compounds. Fascinatingly, the proposed sensor exhibited an excellent electrochemical performance with high sensitivity, selectivity, and reproducibility. The obtained wide linear ranges were 0.05–158.3 and 0.125–225.8 μM for Flut and 4-NP. The low detection limits of 0.016 and 0.040 μM with the higher sensitivities of 5.476 and 9.168 μA μM^–1 cm^–2 were achieved for the determination of Flut and 4-NP, respectively. The practical feasibility of the proposed sensor was studied in tap-water and human-serum samples