Fig. 3From: Visual Cu2+ Detection of Gold-Nanoparticle Probes and its Employment for Cu2+ Tracing in Circuit SystemXPS results of LS-AuNP probes for detecting Cu2+ ions: a 20 μM and b 50 μM. c Zeta potentials of different LS-AuNP samples. d Schematic illustration for detecting Cu2+ ionsBack to article page