A novel ratiometric fluorescent probe for detection of dopamine and cupric ions

In this paper, bovine serum albumin served as the initial materials for preparing a kind of cyan-emitting fluorescent protein nanoparticles (BSA NPs). The BSA NPs were further adopted as a template to synthesize protein nanoparticles-stabilized silver nanoclusters (BSA NPs@Ag NCs) that offered two well-separated fluorescence emission peaks respectively at 470 nm and 670 nm. Dopamine could specifically induce the fluorescence enhancement at 470 nm and the fluorescence quenching at 670 nm of BSA NPs@Ag NCs. Moreover, cupric ions could cause the fluorescence quenching at 670 nm of BSA NPs@Ag NCs just with a negligible impact on the fluorescence intensity at 470 nm. The BSA NPs@Ag NCs can serve as a ratiometric probe for detection of dopamine and cupric ions.