Advanced Nb-doped ZnO/ZIF-8 nanocomposite: a synergistic smart strategy for catalytic functionality in preparation of spiro[indene-2,2′-naphthalene]-4-carbonitriles and antibiotic resistance

, with inhibition zones of 18 and 21 mm, respectively, and a 5-log reduction in viability within 24 h. These empirical findings suggest a potent oxidative-stress-inducing mechanism suitable for combating resistant clinical pathogens. Furthermore, the hybrid composite demonstrated exceptional utility as an outstanding heterogeneous catalyst for the preparation of medicinal substituted spiro[indene-2,2'-naphthalene]-4-carbonitrile derivatives in an ethanol medium, achieving excellent yields (up to 98%) within 20 minutes and retaining high catalytic functionality over five consecutive runs without significant leaching. This study highlights the potential of Nb-doped ZnO/ZIF-8 as a robust dual-purpose composite for antimicrobial applications and sustainable catalysis in green organic synthesis, offering a scalable, environmentally benign paradigm for addressing contemporary biomedical and catalytic challenges.