Highly sensitive detection of dopamine based on gold nanoflowers enhanced-Tb(III) fluorescence

We developed a trace level detection method for dopamine (DA) based on the metal-enhanced fluorescence (MEF) effect of gold nanoflowers (AuNFs). AuNFs prepared were excellent enhancement fluorescence substrates due to their unique morphology with rich edges and sharp quoins. DA was the target analyte and also as a bridge reagent that could regulate the distance between AuNFs and Tb³⁺. The characteristic fluorescence of Tb³⁺ was enhanced significantly through the synergistic effect between the luminescence sensitized by DA and the MEF caused by AuNFs. Under the optimum experimental conditions, the fluorescence intensity of Tb³⁺ at 545 nm demonstrated very significant sensing ability against DA concentration and showed a good linear relationship in the range of 0.80-300 nM and the limit of detection was 0.21 nM (S/N = 3). The proposed method was also validated in serum samples and the dopamine hydrochloride injection samples with satisfactory results.