Fluorometric detection of dopamine based on 3-aminophenylboronic acid-functionalized AgInZnS QDs and cells imaging

Herein, cysteine capped AgInZnS QDs (Cys-AIZS QDs) with a large stoke shift and excellent biocompatibility were synthesized by a one-step aqueous method, followed by modified with 3-aminophenylboronic acid (APBA). Dopamine (DA) as an important neurotransmitter in brain can lead to significantly decrease in the fluorescence intensity of 3-aminophenylboronic acid-functionalized Cys-AIZS QDs (APBA-AIZS QDs) in a large concentration range of 1.5-900 μM. Good linearity can be obtained in the range of 15-120 μM, with a limit of detection (LOD) of 0.65 μM. Moreover, Cys-AIZS QDs and APBA-AIZS QDs were applied to living cells imaging, and Cys-AIZS QDs were applied to the co-localization with lysosomes, indicative of the feasibility of intracellular detection.