Gold nanocluster aggregates-phenol derivative system constructed by van der Waals for ratiometric fluorescence detection of dopamine, norepinephrine, and resorcinol

Abstract

Here, we synthesized gold nanocluster aggregates (GNCA) and constructed a gold nanocluster aggregates-phenol derivative system based on van der Waals for ratiometric fluorescence detection of dopamine (DA), norepinephrine (NE), and resorcinol (Rs), respectively. Novel fluorescent GNCA were rapidly prepared by one-pot method in an alkaline environment regulated by PEI instead of NaOH. PEI wrapped around and connected gold nanoclusters to form GNCA with long fluorescence lifetime and high fluorescent stability. Additionally, Rs was adsorbed on the surface of GNCA via van der Waals to develop the GNCA-Rs system. When NE and DA were introduced to the GNCA-Rs system, two new fluorescence peaks at 513 nm and 474 nm appeared, owing to the fluorescent polycondensation reaction of Rs with NE and DA, respectively. Thus, non-enzymatic fluorescence detections of NE and DA were achieved. When the GNCA-Rs system was used as a fluorescent probe, the linear detection ranges of NE and DA were 0.01–400.0 μM and 0.001–400.0 μM respectively, with detection limits (LOD) of 78.0 nM and 3.0 nM. The high sensitivity was attributed to physical adsorption based on van der Waals interactions and polycondensation processes. Similarly, van der Waals developed a GNCA-DA system with remarkable sensitivity (LOD=1.4 nM) for the detection of Rs. In this study, we not only proposed an efficient approach for constructing fluorescent probes, but also presented a novel strategy for the detection of catecholamines.