A simple and accurate ratiometric sensor for determination of dopamine based on dual-emission carbon dots.

Abstract

Dopamine (DA) is a neuromodulatory molecule that plays critical roles in many biological processes. The dysfunctions of the DA system are closely associated with several nervous system diseases. Therefore, it is urgent to establish a simple and accurate method for DA analysis. In this study, an economic and accurate DA ratiometric sensor was established using dual-emission carbon dots (DE-CDs). DE-CDs were first synthesized by the one-step solvothermal method and two separate fluorescence emission peaks at 340 and 500nm were observed under the excitation of 310nm. In the presence of Hg2+, the fluorescence signal at 340nm was significantly quenched, while the signal at 500nm keeps stable. Upon adding DA, the quenched signal at 340nm was significantly recovered, whereas the signal at 500nm remains stable. Therefore, a novel ratiometric sensor for DA analysis was established. This method shows a good linear range from 500nM to 100μM, and the detection limit was calculated to be 80nM. Moreover, this established method shows excellent specificity and could be applied in real sample analysis, showing great potential for application in clinical research.