Millipore advantage a10 system

Chloroauric acid tetrahydrate (HAuCl₄∙4H₂O), sodium citrate (C₆H₅Na₃O₇∙2H₂O), silver nitrate (AgNO₃), ascorbic acid (AA), dimethyl sulfoxide (DMSO), sodium chloride (NaCl), and CTAB were purchased from Aladdin Bio-Chem Technology Co., Ltd. (Shanghai, China). Azo reporters (Figure S1) were kindly provided from Prof. Tingjuan Gao’s group (Central China Normal University, China). E. coli (ATCC 8099) and S. aureus (ATCC 25923) were supplied by China Center for Culture Collection (Wuhan, China). Tryptone and yeast extract were purchased from Sigma-Aldrich (Saint Louis, MO, USA). Lysogeny broth (LB) was prepared by dissolving tryptone (10 g/L), yeast extract (5 g/L), and NaCl (5 g/L) into the phosphate buffered saline solution (PBS, 10 mM, pH = 7.4), followed by autoclaving at 121 °C in an autoclave (LDZX-50L, Shanghai shenan, China). LB solid medium was prepared by mixing the LB with agar (1.5 g/L, Sigma-Aldrich). Deionized water was drawn from a Millipore Direct Q8 system with a resistivity of 18.2 MΩ cm (Millipore advantage A10 system, Merck, Germany). All chemicals were analytically pure and used without any further purification unless otherwise stated.

s-PBC membranes and hybrid s-PBC/GO nanocomposite membranes were prepared using the solvent casting method. In particular, a 0.3 g/mL polymer solution in DMF was prepared by drying 27 g of commercial s-PBC solution at about 60 °C to get the evaporation of the commercial solvents and then dissolving it in 90 mL of DMF (as revealed by the clear colour of the solution). Finally, 15 mL of the suspension were cast on a Petri dish and left overnight at 60 °C for the complete evaporation of the solvent. In the case of nanocomposites, 0.045 g of GO aqueous solution (1.2 %wt) was added slowly to 60 mL of the polymer solution in DMF, prepared as described above. This final solution was stirred for several hours to get a homogeneous mixture until the solution was dense enough to be cast as described for the s-PBC membrane. Afterwards, the membranes were removed from the Petri dish by dipping the glass plate in deionized water for several minutes. Finally, they were pressed between two Teflon plates and heated in an oven at ambient condition at 150 °C for about 25 min. The membranes were soaked and washed in deionized water produced by a Millipore Advantage A10 system (Merck Millipore, Darmstadt, Germany) at room temperature in order to remove the eventual impurities, such as residual acids, until the soaking solution stabilized at neutral pH [18 (link)].