Design of reduced graphene hydrogel with alkylamine surface functionalization through immersion/agitation method and its adsorption mechanism

Exploring copper (II) porphyrin complexes and their derivatives for electrochemical analysis and biological assessment in the study of breast cancer (MCF-7) cell lines

In this study, several derivatives of tetraphenylporphyrin were synthesized, each with unique meso-substituent groups including phenyl, methoxyphenyl, butyloxyphenyl, octyloxyphenyl, and dectyloxyphenyl. Additionally, their corresponding copper complexes were prepared and thoroughly characterized. The structural confirmation of all compounds was established through CHN elemental analysis, mass spectrometry, and FT-IR spectroscopy. As the number of carbon atoms in the alkyl long-chain increased, a slight red shift in the electronic absorption band was observed, which was attributed to the electronic influence of the alkyl group. DFT analysis indicated that electron density predominantly localized on the porphyrin ring of both the metal free porphyrins and copper (II) porphyrin complexes, with relatively low electron density in the p orbital of the meso-aryl long-chain substituent group. EPR spectroscopy of the Copper (II) ion complexes revealed signals, indicating their paramagnetic properties. Additionally, the Copper (II) tetraphenylporphyrin (CuTPP) complexes displayed two reversible oxidation peaks at +0.97 V and +1.35 V, whereas other derivatives exhibited lower oxidation potentials. The cytotoxicity of these compounds against MCF-7 cell lines was assessed using MTT assay, revealing cytotoxic effects in all cases. Among them, Copper (II) tetrakis (4-methyloxyphenyl)porphyrin (CuTOMPP) demonstrated the highest potential, with an IC50 value of 32.07 μg/mL.

Cu2O/TiO2 decorated on cellulose nanofiber/reduced graphene hydrogel for enhanced photocatalytic activity and its antibacterial applications

Photocatalysis has gained attention as a viable wastewater remediation technique. However, the difficulty of recovering powder-based photocatalyst has often become a major limitation for their on-site practical application. Herein, we report on the successful in-situ preparation of a novel three-dimensional (3D) photocatalyst consisting of Cu₂O/TiO₂ loaded on a cellulose nanofiber (CNF)/reduced graphene hydrogel (rGH) via facile hydrothermal treatment and freeze-drying. The 3D macrostructure not only provides a template for the anchoring of Cu₂O and TiO₂ but also provides an efficient electron transport pathway for enhanced photocatalytic activity. The results showed that the Cu₂O and TiO₂ were uniformly loaded onto the aerogel framework resulting in the composites with large surface area with exposed actives sites. As compared to bare rGH, CNF/rGH, Cu₂O/CNF/rGH and TiO₂/CNF/rGH, the Cu₂O/TiO₂/CNF/rGH showed improved photocatalytic activity for methyl orange (MO) degradation. MO degradation pathway is proposed based on GC-MS analysis. The enhanced photoactivity can be attributed to the charge transfer and electron-hole separation from the synergistic effect of Cu₂O/TiO₂ anchored on CNF/rGH. In terms of their anti-bacterial activity towards Staphylococcus aureus and Escherichia coli, the synergistic effect of the Cu₂O/TiO₂ anchored on the CNF/rGH framework showed excellent activity towards the bacteria.