Eco-friendly, magnetic NiFe₂O₄@sodium alginate-g-poly(3-aminophenol) nanocatalyst for synthesizing bioactive...

A nickel ferrite@sodium alginate-grafted-poly(3-aminophenol)@MXene (NiFe₂O₄@Na-Alg-g-P3AP@MXene) nanocomposite has been developed through three critical steps: (1) synthesizing NiFe₂O₄ nanoparticles via co-precipitation, (2) preparing Ti₃C₂ MXene by selective etching of aluminum from Ti₃AlC₂, and (3) integrating MXene and nickel ferrite into the nanocomposite via in situ polymerization. The catalyst was comprehensively characterized using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDX), and vibrating sample magnetometry (VSM). The NiFe₂O₄@Na-Alg-g-P3AP@MXene nanocomposite exhibited outstanding catalytic performance in synthesizing novel polyhydroquinolines (PHQs). These derivatives were obtained in excellent yields (85-95 %) using alkylene-bridged bis-aldehydes, 4-formylphenyl 4-methylbenzenesulfonate, and 3-aryl-pyrazole-4-carbaldehyde under optimized conditions, with remarkably short reaction times (40-90 min). The synthesized PHQ derivatives demonstrated potent antioxidant activity (18.9-94.8 % inhibition) and broad-spectrum antibacterial efficacy against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Salmonella enteritidis. Furthermore, the nanocomposite catalyst displayed exceptional stability and reusability, retaining >90 % efficiency over five consecutive catalytic cycles. Notably, the polyhydroquinolines also exhibited prominent anticancer activity against MCF-7 breast cancer cells.