Electron Transfer-Driven Nanozymes Boost Biosensor Sensitivity via a Synergistic Signal Amplification Strategy

The conventional gold nanoparticles (AuNPs) with insufficient brightness face substantial challenges in developing a sensitive lateral flow immunoassay (LFIA). Herein, multibranched manganese–gold (Mn–Au) nanoparticles (MnAuNPs) with a Au core–Mn shell nanostructure were synthesized by a one-pot method. The Mn shell of valence-rich and Au core of high electron transfer efficiency endowed MnAuNPs with oxidase-like activity, which oxidized 3,3′,5,5′-tetramethylbenzidine (TMB) only by electron transfer. Ox-TMB, which was the oxidation product of TMB, is an excellent photothermal agent. Furthermore, the synergistic photothermal effect of ox-TMB and MnAuNPs significantly enhanced the photothermal conversion…