A highly selective and sensitive fluorescent nanosensor for dopamine based on formate bridged Tb(III) complex and silver nanoparticles

Highly selective determination of dopamine (DA) over other catecholamines is an urgent need for the precise diagnosis and therapy of DA related diseases. Herein, a new formate-bridged Tb(III)-complex and silver nanoparticles (AgNPs) enhanced fluorescent nanosensor was constructed. HCOO− acted as a co-ligand of Tb(III) and also as a linker between the Tb(III) complex and AgNPs and more readily combined with the primary amine of DA than with epinephrine (EP). The formate-bridged action strengthened AgNPs-based surface enhanced fluorescence of the Tb3+-DA complex and improved the selectivity towards DA. Under neutral buffer conditions, the detection limit for the assay of DA was down to 0.15 nM (S/N = 3) with a linear range from 0.5 nM to 100 nM (R2 = 0.9978). Furthermore, the nanosensor could successfully distinguish DA from EP.