Fluorescent silver nanoparticles for sensitive and selective detection of dopamine

Herein, fluorescent silver (Ag) nanoparticles (NPs) were synthesized by using a simple chemical reduction method. Further, it was functionalized with 1,4-mercaptophenyl boronic acid (MPBA) and 4'-aminobenzo-18-crown-6 (ABCE) for highly sensitive and selective fluorescence detection of dopamine (DA). Upon adding DA, quenching was observed in the fluorescence intensity of Ag NPs. The mechanism behind such fluorescence modulations in Ag NPs were discussed through static quenching, dynamic quenching, static/dynamic quenching and fluorescence resonance energy transfer (FRET). The limits of detection (LOD) of fluorescent Ag NPs for DA was calculated to be 5.3934 x 10(-6 )M (S/(N) over tilde3). The fluorescent Ag NPs was also showed better selectivity in the presence of excess ascorbic acid (AA), uric acid (UA) and other metal ions. The obtained results suggest that our fluorescent Ag NPs can be successfully applied as a probe for the detection of DA using real biological samples.