A simple dopamine detection method based on fluorescence analysis and dopamine polymerization

Dopamine (DA) is a significant catecholamine neurotransmitter in the brain of mammal, and DA is one biological index of some diseases at the same time. Due to various drawbacks in clinical trials of the existing methods for detecting dopamine, there is an urgent need for rapid and sensitive detection methods to diagnose and monitor these diseases. In this study, we report a simple, effective, sensitive, non-toxic and environmentally friendly method for the DA detection based on fluorescence analysis, more specifically, we use the characteristic of dopamine, dopamine oxidative polymerization, so as to achieve testing of dopamine. The way only uses a common alkali, polyethyleneimine (PEI), to start the polymerization process, and make the experiment very simple and cheap. The optical properties of polydopamine (PDA) nanoparticles which formed under different response times and different concentrations were studied for the first time. After the experimental conditions were optimized, a good linear relationship was obtained from 1.0–200 μM with the correlation coefficient of 0.99904 and the detection limit was 0.3 μM. This method is highly selective and has great potential for detection of dopamine related diseases.