Ag–Cu@FA hydrogel-nanocomposites as catalyst and SERS substrate for the oxidation of TMB

Abstract Ag–Cu@FA hydrogel-nanocomposites were prepared by embedding copper nanoclusters (CuNCs) and silver nanoparticles (AgNPs) in the hydrogel matrix of folic acid (FA). This nanocomposites exhibited high catalytic activity for the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2. On the basis of the excellent SERS properties of Ag–Cu@FA, the reaction process can be in situ monitored by SERS.