This study investigates the modification of polylactic acid (PLA) by the incorporation of graphene oxide (GO) and metal oxides (ZnO and CuO), with the aim of developing efficient CO₂ sensors. Key properties, including total dipole moment (TDM), energy gap (ΔE), molecular electrostatic potential (MESP), and density of states (DOS), were calculated using density functional theory (DFT) to gain insight into the interactions between the composites and CO₂ gas. Experimental techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and optical confocal microscopy were used to validate the material composition and bonding mechanisms. The analysis revealed the presence of SiO₂ impurities in the PLA matrix, which could potentially affect the sensing behavior of the composite. The composites demonstrated effective CO₂ sensing capabilities in experimental tests. This combined theoretical and experimental approach demonstrates that PLA/GO/metal oxide composites offer significant potential for sustainable CO₂ sensing, contributing to air quality monitoring and greenhouse gas regulation.

Single crystal X-ray studies of regioselectively synthesized fluoro-substituted dispiro-oxindole 9 revealed that the structure belongs to the monoclinic space group P2₁/n with four molecules in the unit cell. The structure was also investigated by AM1, PM3, and DFT studies. Compound 9 exhibits high potency against the HeLa cell line.

An anti-oncological active spiro-oxindole 7 was synthesized regioselectively via a [3+2]-cycloaddition reaction of azomethine ylide to exocyclic olefinic linkage of 4-piperidone 6, exhibiting properties against diverse tumor cell lines including leukemia, melanoma and cancers of the lung, colon, brain, ovary, breast, prostate, and kidney. Compound 7 crystallizes in the monoclinic system and P21/c space group with four molecules in the unit cell. The structure was also studied by AM1, PM3 and DFT techniques. DFT studies support the stereochemical selectivity of the reaction and determine the molecular electrostatic potential and frontier molecular orbitals.