Fig. 1: Electron microscopy images of Au modified carbon thread for simultaneous heavy metal detection.

a Plain thread at a scale of 10 µm, b AuNPs deposited thread at a scale of 10 µm, c plain thread at a scale of 1 µm, d AuNPs deposited thread at a scale of 1 µm, e elemental mapping and composition of plain thread, f elemental mapping and composition of AuNPs deposited thread.