2.3. Modification and characterization of the PCTE membrane A nano-porous polycarbonate track-etched (PCTE) membrane (100 nm) was used for surface modification. The drop coating method was used to add GO to the PCTE membrane surface. The round membrane was arranged on the circular planar base of a Petri dish and the surface of the membrane was coated by the pipetting method. The membrane to be coated was arranged with the help of forceps and GO was uniformly dropped onto the surface of the membrane by a micropipette; the coated membrane was kept overnight at room temperature. In this time period, the surface of membrane was covered by a thin layer of GO. The GO-functionalized membrane was characterized by inverted microscopy, SEM, EDC/EDX, and TGA (see Section 2.2) and used for the FT-IR, Ag-Ab interaction studies (described below, Section 2.4).