Detection of tannic acid exploiting carbon dots enhanced hydrogen peroxide/potassium ferricyanide chemiluminescence

Recently, ultra-weak chemiluminescence (CL) systems have become one of the focuses of increasing attention. As one of them, H2O2-K3Fe(CN)6 system had also been studied. However, no attempts had been made to investigate the analytical applications of this system based on carbon dots (CDs). In this paper, nitrogen-doped carbon dots (FNCDs) were synthesized using formaldehyde as a coreactant, and it acted as a new fluorophore instead of conventional fluorescent dyes to enhance the CL signal of H2O2-K3Fe(CN)6 system, in which the excited-state FNCDs was the final emitting species, and was probably produced by the electron transfer and energy from reactive oxygen species. Interestingly, tannic acid (TA) could dramatically suppress the CL intensity of FNCDs-H2O2-K3Fe(CN)6 system. Under the optimum conditions, a linear relationship existed between reduced CL intensity and logarithm of TA concentration in range between 0.2 and 10.0 μM with a detection limit of 39.3 nM. The method was applied to the quantitative analysis of TA concentration in red wine.