Functionalized nanofibrous nylon 6 membranes for efficient reusable and selective separation of laccase enzyme

The development of biomolecules adsorbent with superb efficiency and large processing throughput is of great importance for separation and reusing of enzymes in its free form in various vital industries. Herein, laccase enzyme adsorbent was prepared by carboxylation of nanofibrous nylon 6 membranes (Ny NFM) to form complex with copper metal ions [Ny-CCA-Cu(II)] with high selectivity for laccase adsorption with adsorption capacity 220 mg.g^-1 within 4 h. The prepared nylon NFM provides a promising candidate for separation and use of laccase enzyme in its free form for several times without significant change in its activity. Moreover, [Ny-CCA-Cu(II)] showed dynamic binding efficiency of 160 mg g^-1 which was achieved solely by a gravity filtration, as well as good reusability of [Ny-CCA-Cu(II)] at least for 5 cycles. The results were due to stable physical and chemical structures, highly tortuous open-porous structure of the nanofibrous membranes, and incorporated Cu⁺² complex in [Ny-CCA-Cu(II)]. This simple approach may introduce a way for the design and development of a cost-effective, environmentally friendly and selective adsorptive membranes to recover the valuable enzymes in industrial applications.