Fluorescence detection of dopamine based on nitrogen-doped graphene quantum dots and visible paper-based test strips

Abstract

Dopamine (DA) was sensitively detected using a label-free fluorescence method using nitrogen-doped graphene quantum dots (N-GQDs) as effective probes. The detection of DA was also performed on the N-GQD immersed filter paper. The fluorescence intensity of the N-GQDs was effectively quenched upon addition of DA. There was a good linear relationship between the fluorescence intensity of the N-GQDs and the DA concentration in the range of 1–200 μM, with a detection limit of 0.07 μM. The proposed method was facile, sensitive, and fast for DA detection with simple operation. DA in real serum samples was successfully detected with satisfactory results. Significantly, this fluorescent probe was used to fabricate paper-based test strips for visual detection of DA for the first time, which validated the potential on-site application.