Silver paste

The PEDOT:PSS solution filtered with a nylon syringe filter (pore size = 0.2 μm) was dripped onto the fabric substrate (5.0 × 5.0 cm²). The solution was instantaneously spread out over the textile by penetrating into the fabric pores, so the first sample (sample 1) of the E-textiles was completed after drying by heat gun. The second sample (sample 2) was prepared by immersing sample 1 into the methanol/DMSO solution (4.5 wt.% of DMSO in methanol) at room temperature for 7 min, followed by heat-gun drying. Two side edges of the sample were coated with silver paste (Sigma-Aldrich, St. Louis, MO, USA) and then placed at room temperature for drying.

Sensors based on modified PET TeMs were obtained according to References [19 (link),21 (link)] by magnetron sputtering of platinum with average thickness of 40–50 nm using mask on both sides of the membrane. These surfaces were connected to potentiostat EmStat 3+ (PalmSens) through 0.4 mm diameter copper cables, which were glued to metalized membrane using silver paste (Sigma-Aldrich, Seoul, South Korea). Connections were isolated by fingernail varnish and wax. Diameter of platinum surfaces is 5 mm. One side of membrane was used as working electrode, another side as counter electrode, Ag/AgCl electrode in 1 M KCl solution was used as reference electrode. Electrochemical analysis was performed by square wave anodic stripping voltammetry (SW-ASV) using standard solution of Cu²⁺, Pb²⁺, and Cd²⁺ in 0.1 M sodium acetate. Before the measurements, sensors were kept in analyzed solution for a certain time. Then applying −1.2 V for deposition time of 120 s and scanning from −1 V to 1 V at a frequency of 50 Hz and an amplitude of 20 mV, SW-ASV was performed.