A “traffic light” signal ratiometric fluorescence sensor for highly sensitive and selective detection of dopamine

As a neurotransmitter with important biological properties, dopamine (DA) plays a vital role in the nervous system of the human body. In this paper, Tb-dipicolinic acid (DPA), Eu-DPA, and Tb/Eu-DPA with green, red, and pale-yellow fluorescence are synthesized to construct “traffic light” sensor for detecting DA, based on the characteristic reaction of resorcinol (Rs) and DA. Through the energy transfer and quenching effects, the fluorescence signals of the “traffic light” sensor are weakened, while the blue fluorescent product is enhanced. Moreover, the sensing system shows obvious chroma change from green, red, and pale-yellow to blue, respectively. The ratiometric fluorescence signal change and chroma change enable the detection of DA with good sensitivity, accuracy, high selectivity and anti-interference ability. In addition, the method has good application for DA detection in serum samples and injection. More importantly, this study combines the “traffic light” sensor with characteristic reaction of Rs and DA for the first time, which not only broadens the applications of detecting DA in the initial monitoring and early clinical diagnosis of related diseases, but also provides a new idea for designing optical sensors with excellent performance based on characteristic reaction. ● The “traffic light” probes with excellent optical properties are simply prepared. ● DA is detected using “traffic light” sensor coupled with the reaction of Rs and DA. ● The sensitivity of detecting DA is improved by ratiometric fluorescence method. ● Selectivity is enhanced by introducing the characteristic reaction of Rs and DA. ● The fluorescence colors are changed visibly from green, red, pale-yellow to blue.