Green synthesis of Cu/Fe3O4 nanoparticles using green tea extract: Evaluation of its catalytic activity, antioxidant and anti-colon cancer effects

[Display omitted] •Green synthesis of Cu/Fe3O4 nanoparticles using green tea extract.•Green tea extract was used as a green reducing agent and an excellent stabilizer.•Fe3O4@G.tea/Cu nanocomposite have a suitable anticancer activity against colon cell lines.•Fe3O4@G.tea/Cu nanocomposite have good antioxidant activity. A sustainable biogenic synthesis for the preparation of green tea plant extract engineered novel magnetic nanocomposite (Fe3O4@G.tea) has been represented in this research. The biocompatible composite was then fabricated with in situ prepared Cu NPs using the green tea derived biomolecules avoiding any harsh chemicals, thus making the procedure absolutely green. The electron rich phytochemicals were additionally used to stabilize the adorned NPs from aggregation or aerial oxidation. Physicochemical features of the ensuing Fe3O4@G.tea/Cu nanomaterial was ascertained over a range of instrumental methods, viz., FT-IR, SEM, EDX, elemental mapping, TEM, VSM, XRD, and ICP-AES analysis. Catalytic properties of the bio-nanomaterial were assessed by the synthesis of diverse pyrano[3,2-c]chromene moieties following a multicomponent reaction (MCR) under eco-friendly conditions. Diverse aromatic and heteroaromatic aldehydes were used in the reaction to afford the products in excellent yields. Reusability of the nanocatalyst was demonstrated by easy magnetic decantation from the reaction medium and subsequent recycling for 8 consecutive runs without considerable loss in its activity. Furthermore, the Fe3O4@G.tea/Cu bio-nanomaterial was employed in the biological evaluation against reducing the proliferation of human colorectal cancer and investigating the cytotoxicity against two colorectal cell lines, HT-29 and Caco-2 respectively following MTT assay. The studies documented an increase in % cell viability with increase in material concentration and the corresponding IC50 values obtained as 384.2 μg/ml and 254.6 μg/ml respectively. Again, anti-oxidant activity of the material was determined by DPPH radical scavenging analysis.