A bifunctional sensor based on Au-Fe3O4 nanoparticle for the detection of Cd2+

Abstract A bifunctional sensor based on Au-Fe 3 O 4 nanoparticles (NPs) modified by ethyl 1-(2-(3′,4′-dihydroxyphenyl)-2-oxoethyl)-1H-1,2,3-triazole-4-carboxylate (ETC) was developed. Due to the coordination interaction between cadmium (Cd 2+ ) and ETC, Cd 2+ induced the aggregation of Au-Fe 3 O 4 NPs from dispersion, concomitant with a change in UV–vis spectra and transverse relaxation time ( T 2 ). The combined signals provided high selectively for Cd 2+ ions.