A simple and convenient fluorescent strategy for the highly sensitive detection of dopamine and ascorbic acid based on graphene quantum dots

Publication date: 1 November 2018

Source: Talanta, Volume 189

Author(s): Hua Liu, Ning Li, Huiqi Zhang, Feng Zhang, Xingguang Su

Abstract

In this paper, a simple and convenient fluorescent "turn off-on" strategy for the highly sensitive detection of dopamine (DA) and ascorbic acid (AA) based on graphene quantum dots (GQDs) was developed. DA and GQDs can form the DA-GQDs complex due to the electrostatic interaction and hydrogen bonding. The interaction between Cu²⁺ and the catechol moiety of DA-GQDs complex could lead to strong fluorescence quenching of GQDs. When AA is introduced into the system, AA can reduce Cu²⁺ to Cu⁺, disturbing the interaction between Cu²⁺ and DA-GQDs complex and resulting in the fluorescence recovery of GQDs. Thus, a sensitive and convenient sensor for the detection of DA and AA was developed. Under the optimized experimental conditions, the fluorescence intensity was linearly correlated with the concentration of DA and AA in the range of 0.5–120 µmol L⁻¹ and 0.05–6 µmol L⁻¹ with a detection limit of 0.16 µmol L⁻¹ and 0.021 µmol L⁻¹, respectively. Meanwhile, the proposed method has potential applications on the detection of DA and AA in human urine and serum samples.

Graphical abstract

We developed a simple and convenient fluorescence "turn-off-on" platform for dopamine and ascorbic acid assay based on the specific interaction between dopamine on the surface of graphene quantum dots and Cu²⁺ and the reduction of ascorbic acid.

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