Enhanced Tb(III) fluorescence on gelatin-coated silver nanoparticles in dopamine detection

A composite fluorescent nanoprobe based on metal enhanced fluorescence (MEF) effect of gelatin-coated silver nanoparticles ( [email protected] ) was developed for selective and sensitive detection of dopamine (DA). The characteristic fluorescence of Tb(III) was using as the detection signal and [email protected] served as substrates of the MEF. Gelatin with rich amine and carboxylic groups was used not only as a co-ligand of Tb(III) complex, but also as a bridging substance and a spacing material for improving the MEF of [email protected] on the intrinsic luminescent intensity of Tb(III). Under the optimal conditions, the increment of the fluorescence intensity (measured at 307/544 nm as excitation/emission wavelength) of the system increased linearly with the concentration of DA in the range of 0.80–100 nM ( R 2  = 0.9937) and 100–1000 nM ( R 2  = 0.9978). The fluorescent probe greatly improved Tb(III) luminescence, which paved the way for sensitive detection with a low detection limit of 0.54 nM. It also showed good selectivity among other neurotransmitters . This work was successfully applied to the determination of DA in human serum samples with recoveries ranging from 99.8 to 102.2%. We believe that the Tb(III) [email protected] composite fluorescent probe can be developed as a new approach for DA detection.